WeatherNation Blog

Blizzard Today, More Systems Coming!

This morning opens to the second system of the triple threat scenario we discussed last week with the addition of another triple threat on the horizon. A sample warning out of Rapid City, South Dakota from the current system is below:


URGENT – WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE RAPID CITY SD
704 AM MDT MON MAR 30 2009

ANOTHER SPRING BLIZZARD WILL POUND NORTHEAST WYOMING AND WESTERN SOUTH DAKOTA THROUGH TONIGHT.

A STRONG LOW PRESSURE SYSTEM IS MOVING OUT OF THE NORTHERN ROCKIES THIS MORNING AND WILL CROSS THE NORTHERN PLAINS TODAY.

THIS STORM SYSTEM WILL BRING WIDESPREAD SNOW TO THE REGION FROM THIS MORNING THROUGH TUESDAY MORNING. CONSIDERABLE BLOWING AND DRIFTING SNOW ARE OCCURRING WITH STRONG NORTHWEST WINDS.

BLIZZARD CONDITIONS ARE OCCURRING ACROSS MUCH OF NORTHEAST WYOMING AS WELL AS THE PLAINS OF NORTHWESTERN SOUTH DAKOTA. THE SNOW IS EXPECTED TO DECREASE FROM WEST TO EAST TONIGHT.

SNOWFALL TOTALS OF 10 TO 16 INCHES CAN BE EXPECTED OVER NORTHEAST WYOMING AND ON THE PLAINS OF WESTERN SOUTH DAKOTA ALONG AND NORTH OF I-90. SOUTH OF I-90 SNOWFALL TOTALS OF 5 TO 10 INCHES CAN BE EXPECTED. STRONG UPSLOPE FLOW WILL DROP 20 TO 30 INCHES OF SNOW OVER THE NORTHERN BLACK HILLS.


Dakotas To Be Blasted, More Systems To Come
The second low of our triple threat scenario discussed last week is performing quite well as blizzard warnings and winter storm warnings cover the majority of the great plains at this time.

Accumulations will be quite respectable over the Dakotas and into Minnesota with 6″ totals over most of South Dakota, southern North Dakota, and a large portion of central and northern Minnesota with accumulations greater than one foot likely in many areas.

Winds will be a strong factor with this system with averages of 40+mph and stronger gusts in many areas will result in the near impossibility of travel with whiteout conditions widespread in many areas.

Today we will utilize our usual graphics to discuss where our current storm will go, and where those in the future may approach.


3.5 Day Ptype Animation
7.5 Day Minimum Temps
7.5 Day Ptype Anim
7.5 Day Maximum Temps


Track of Current Blizzard
Utilizing our 3.5 Day Precipitation Type Animation our current low is forecast to follow a similar track as was forecast last week. From the opening frame of our 06z run (F003hr valid 5am edt) snows are shown across Wyoming, Montana, and the Dakotas. From that point through F021hr valid 11pm edt this evening, we see a smooth generally ESE migration where most of South Dakota, southern North Dakota, and a the northern fringe of Nebraska is forecast to receive snows, and at this point little or nor mixed precipitation is forecast to occur.

However, from this evening through the next frame (F024 hr valid 2am edt Tuesday) and into the morning we see the potential for mixed pop up as precipitation begins to fall in Minnesota, and maintain itself through 8am edt (F030hr) tomorrow morning in Minnesota, and also spreading into Wisconsin as a finite boundary between liquid, mixed, and frozen precipitation exists across Minnesota and Wisconsin.

By 8pm tomorrow evening (F042hr) the low is centered over Minnesota with mostly snow remaining for the state with the exception of liquid possible for the extreme southeastern corner, while the rain/snow line divides Wisconsin just north of the central portion of the state. Michigan still has the opportunity for mixed in the U.P. with snow on the western fringe, while rain will fall through the southern Great Lakes states into the deep south.

By 8am edt Wednesday (F054hr) the low persists in northern Minnesota with rain extending from eastern Michigan south into northern Florida, where by 8pm on Wednesday Evening (F066hr) the low has mostly exited the northern tier, with the second of our triple threat beginning to show itself in the central plains, Happy April Fool’s Day!

Our last valid frame for the 06z run F084hr shows an area of lower pressure centered between Arkansas and Oklahoma, so from here let’s switch to our 7.5 day Precipitation Type Animation and notice that at the same valid time (F084) our low is centered slightly more east than on our 3.5 day product.

Advancing through F090 hr valid 8pm Tuesday April 2, our low is forecast to dig slightly deeper while moving just north of Memphis where by 8pm on Friday it is centered over basically Columbus, Ohio. Notice throughout these frames mostly liquid precipitation is forecast to occur, with a slight opportunity for snow in western Arkansas.

From Columbus, our second low dances a little N/S jig before heading up the eastern coast and into Canada, while around 2am EDT (F120hr) Saturday Morning, we have another Dodge City low becoming more pronounced.

The forecast trajectory for our third low of this week’s triple threat is a generally eastward progression. Advancing from the 2am Frame above through 8pm next Sunday Evening the center of circulation basically straddles the Kansas / Oklahoma state line with the usual distribution of snows to the north and west, and rains to the south, where by 8am edt on Monday MOrning the center of circulation hovers above Cincinnati, with snows along the western flank of the system, according to this graphic to include Chicago, IL.

You may of course view our 7.5 Day Forecast Maximum and Minimum temperature animations to view temperature distributions associated with these movements. The SPC has also issued a Convective Outlook for today that includes a slight risk category for southeastern Kansas, and northeastern Oklahoma, but I’m not overly excited about it, other than the potential for large hail. More interesting will be the potential for severe weather with our developing second area of lower pressure, more on that later.

Please be sure to view our Advisory and Radar Centers for the latest updates and developments.

As always stay tuned to your favorite weather outlet, stay informed, and stay safe!

cheers,

–patrick

More Monster Snows, Tornadoes & Flooding

The severe thunderstorms we discussed would occur this week certainly have not let us down, and today is another day with an elevated threat, where the SPC has issued a Moderate Risk in their Convective Outlook category including the areas of northern Louisiana, southern Arkansas, and most of Mississippi, including the Mississippi Delta where wonderful food, great people, and excellent chasing territory predominate. Much of the southeast from Oklahoma to Georgia are under a “Slight” risk classification, however such an issuance should not be taken lightly as often severe thunderstorms and tornadoes occur under such a heading.

Remnants of yesterday’s activities are slowly moving out of the southeast where three possible tornadoes were reported in the Florida Panhandle, but the main threat for today will be in the area outlined above later this afternoon and this evening.

The threats today revolve around the same issues we have discussed all week, with the addition of a greater variance in the atmospheric column between the warm gulf air at lower levels and cooler air associated with our moving system aloft. This will result in heightened thermodynamic forcing with the likelihood today of very large hail, the usual threat of winds and strong tornadoes. The storms will become supercellular this afternoon forming into disorganized linear structures as the evening progresses.

Day One Convective Outlook


Blizzard Still Going, More Systems To Come
We discussed our triple threat scenario and the developing systems over the last week or so, our current low is certainly performing up to expectations, and the threat of mixed precipitation we forecast seems to be right on track.

Today we will utilize our usual graphics to discuss where our current storm will go, and where those in the future may approach.

3.5 Day Ptype Animation
7.5 Day Minimum Temps
7.5 Day Ptype Anim
7.5 Day Maximum Temps

The first frame of our 12z 3.5 Day Precipitation Type Animation is valid 11am this morning, clearly depicting that ending at that time a respectable area of mixed precipitation is possible on a line running from near Lubbock, through Childress and into western Oklahoma, while snows still predominate in the Texas Panhandle, Cherokee Strip, western Kansas, southeastern Colorado, and eastern New Mexico.

The second frame valid at 2pm EDT extends the potential for mixed precipitation in Oklahoma and even into southern Kansas, while snows are still favored for the previous regions.

Advancing through to F021 Valid 5am EDT tomorrow, our low is shown to accelerate through northeastern Oklahoma with snows trailing along the southwestern flank, and from here she begins a faster move to the northeast.

F036hr Valid 8pm EDT we see a twinge of an area near Chicago showing the potential for mixed precipitation while snows are still falling in northeastern Oklahoma, southeastern Texas through Missouri and into Iowa. As we advance a few frames through 5am on Sunday, the snow band becomes more clearly defined with snows covering the majority of Illinois, eastern Missouri, Wisconsin, and into Michigan, where the potential for mixed exists over the previous hours.

By F051hr 11am EDT on Sunday snow is still in the cards for Chicago, Indiana, and Michigan, but also take a look to the west. Do you see something we’ve mentioned a few times developing? =)

By 8pm Sunday evening, our first low is nearly finished with us, with lingering snows possible in Ohio, Michigan, and of course the Ridge-and-Valley provinces of the Mid Atlantic states. While the second low of our triple threat scenario is showing itself in the Rockies. Go ahead and fast forward through F075hr, 11am EDT on Monday Morning and notice the second low centered in Nebraska with snows running through both Dakotas, southeastern Montana, and eastern Wyoming.

By the last forecast hour (F084) for our 3.5 Day animation valid 8pm EDT Monday Evening, the second low is still in northeastern Nebraska with a forecast central pressure of 995mb, with snows still trailing through both Dakotas, central and western Nebraska and lighter snows possible in the fringes.

OK, so now we are through 8pm EDT next Monday morning, from here pull up our 7.5 Day Precipitation Type Animation where we left off previously, so F084hr Valid 8pm EDT on Monday March 30. Notice that the low is forecast to be in a similar position, with a wider band of snows possible since as you recall this product is at 6 hour intervals instead of 3. So where does it go from here?

Interestingly, it seems Minnesota may have have an attractive force, as we advance through 8pm EDT on Tuesday morning, it is centered on the border of Minnesota and Iowa with a forecast central pressure of 994mb. By 8pm next Tuesday, central pressure rises slightly while the low centers itself over Rochester. But do you see anything else starting to develop? =)

Threat 3 begins forming at the frame above, but advance through F120hr valid 8am EDT next Wedesday, where it appears it may wish to become another ‘Dodge City Low.’ However, forward through 8pm on Wednesday (F132), notice how she digs like we previously forecast to become perhaps another Panhandle hook.

To give you an idea where this low is heading, forward all the way through next Friday April 3, (F168hr) at 8am EDT. She looks to dig deeply doesn’t she, all the way to 980mb! However, recall i’ve mentioned before that often times the vertical stacking, or depth of central pressure often fluctuates with models especially out this far, but it surely could be interesting! Notice Minnesota is in the line of fire again.

The last frame we can utilize is F180hr valid 8pm EDT next Friday where the third low in our triple threat scenario eases up to 985mb, but notice closely the division of snow and rain.

Additionally what’s going on off the coast of British Columbia on the last frame? =)

Snow accumulations with our first low will continue to be respectable where totals of up to 1 foot in portions of Oklahoma and Kansas are easily obtainable. As she turns to the northeast there we be a very long swath of 6″ snows running through Kansas, Missouri, and into Illinois. The interesting thing will be the totals once she reaches Chicago.. very tough to tell. I am going to say the best totals look to be from Oak Park to the north and east, where 6″ would be a good bet. South of Oak Park on a line from say Naperville to Aurora, perhaps 4-6″. It will be interesting to see how it pans out and if the models change their minds over the next few days.

The icing we mentioned is certainly in the cards for many areas, but the best chance for accumulation is in Oklahoma, Kansas and northwestern Missouri today, as well as a splinge in northern Illinois, not to forget the potential we mentioned in Michigan coming up.

Flooding is still going insane for the north. Our forecast yesterday still hold true, or simply utilize our fantastic Rivers & Lakes Center mentioned in yesterday’s post to view live and updated conditions.

Please be sure to view our Advisory and Radar Centers for the latest updates and developments.

As always stay tuned to your favorite weather outlet, stay informed, and stay safe!

cheers,

–patrick

Blizzard, Tornadoes, Flooding Oh My!

Winter Weather Warnings This Morning
Our discussions over the last week for the developing low we have christened “Bubba” are coming together this morning. Blizzard watches were issued yesterday afternoon, and Blizzard Warnings were released early this morning for eastern Colorado and western Kansas, while blizzard watches are still active for the western Texas Panhandle, and a teenie slice of central Kansas. Click the image at left, or here to see the current state of advisories in our Advisory Center.

Very impressive snow totals will accompany Blizzard Bubba as he builds in Colorado and Kansas, with snows forecast to continue along the track we discussed yesterday, and will update again tomorrow morning. The city that will likely garner the most attention in the national media is of course Denver, Colorado, where one of the lowest snow totals for the season on record of 18.8″ will change dramatically as the storm moves through.

The blizzard warning for Denver is below for your convenience:



BLIZZARD WARNING
Issue Date: 257 AM MDT THU MAR 26 2009
Expiration: 600 AM MDT FRI MAR 27 2009

MAJOR WINTER STORM MOVING INTO NORTH CENTRAL AND NORTHEAST COLORADO…

A LOW PRESSURE SYSTEM WILL STRENGTHEN AS IT MOVES FROM WESTERN WYOMING TO NORTHERN NEW MEXICO BY TONIGHT. SNOW WILL SPREAD FROM THE MOUNTAINS ACROSS THE PLAINS OF NORTHEASTERN COLORADO THIS MORNING AS THE LOW APPROACHES AND A COLD FRONT WILL BRING COLDER AIR AND GUSTY NORTH WINDS AS WELL. BY MIDDAY MODERATE TO HEAVY SNOW WILL BE WIDESPREAD ALONG WITH WINDS GUSTING AS HIGH AS 45 MPH. THIS WILL CREATE BLIZZARD CONDITIONS ON THE PLAINS AS WELL AS WIND PRONE AREAS IN THE FOOTHILLS.

CONDITIONS ARE EXPECTED TO BE WORST THIS AFTERNOON AND EVENING WHEN BOTH THE WINDS AND SNOWFALL WILL PEAK. CONDITIONS WILL IMPROVE THIS EVENING IN THE NORTHERN PART OF THE AREA BUT BLIZZARD CONDITIONS ARE EXPECTED TO PERSIST IN AREAS SOUTH OF INTERSTATE 70 MUCH OF THE NIGHT. SNOWFALL TOTALS BY FRIDAY MORNING WILL RANGE FROM AROUND 6 INCHES IN THE NORTHEAST CORNER OF THE STATE TO BETWEEN 8 AND 16 INCHES IN THE DENVER METRO AREA WITH UP TO TWO FEET OF SNOW IN AREAS SOUTH AND WEST OF DENVER. THE SNOWFALL COMBINED WITH PROLONGED WINDS WILL CREATE SIGNIFICANT DRIFTING OF SNOW ON THE PLAINS.

RESIDENTS OF NORTH CENTRAL AND NORTHEASTERN COLORADO SHOULD MAKE NECESSARY PREPARATIONS FOR THIS STORM EARLY THIS MORNING. IF TRAVEL CANNOT BE COMPLETED EARLY THIS MORNING CONSIDER WAITING UNTIL CONDITIONS IMPROVE ON FRIDAY. ROAD CLOSURES ARE LIKELY LATER TODAY AND TRAVEL WILL BE HAZARDOUS WHERE IT IS STILL POSSIBLE.


Thunderstorms and Tornadoes
Yesterday we mentioned that severe weather would occur for at least the next few days in the southeast, and today we can extend that for another day. We also mentioned the possibility that the SPC might extend their convective outlook to a moderate risk instead of slight risk, but that did not occur. However, at least 8 tornadoes have been reported so far, and in the city of Magee, MS various AP reports state that at least 60 houses were damaged and one church destroyed. A good reference article on the developing story is from FoxNews.com. Storm assessment reports are not available yet for yesterday’s storms, the local NWS office that covers Magee and the surrounding area is out of Jackson, and their site is here.

Update: The Clarion Ledger out of Jackson, Mississippi reports that Governor Haley Barbour has officially declared a state of emergency for many counties affected by yesterday’s severe storms, and that a “path of substantial damage” was noted for the Magee tornado that “… tore through the north side of town.” Other reports and pictures are available with the Clarion Ledger article.

Click the image at right or here to view storm reports by type and date. It is handy when viewing storm reports to choose the “range selector” under the date toggle forms, and choose “past 2 or 3 days” to ensure the relevant information you seek is pulled up from the database.

Storm Reports – Click For Live Data

Rivers & Lakes Center – Click for Live Data
Flooding
The national media has given respectable coverage to flooding that is and will continue to occur in the Dakotas and Minnesota. Not to “toot our own horn” but a fantastic reference for river conditions and flood outlooks is our River Center.

As you open the link, scroll down until you see the map and notice “River & Lake Stage Conditions”, with the scale of “Normal (color green)” to “Major Flood (color purple),” and also the Outlook thumbnail in the right menu. For this example I advise clicking the boundary between North Dakota and Minnesota.

After doing so hold your mouse cursor over the large purple dot just south of Fargo, and notice the flyout that says “Red River of the North… Stage 38.67 feet – Major Flooding.” Then click the dot. I chose this for you since it is garnering the most media attention.

Now what comes up is action stages and flow information for the river, then below a Forecast of projected river stages, and historical data. Note that currently (current is highlighted when you scroll down) we are at 38 feet + but as we move forward in time, a peak of 41 feet is forecast to occur by 1pm on Saturday, March 28, and continue at that level through next Tuesday March 31, and then very slowly begin tapering off, remaining at a major flood stage through April 2, a week from today.



Please be sure to view our Advisory and Radar Centers for the latest updates and developments.

As always stay tuned to your favorite weather outlet, stay informed, and stay safe!

cheers,

–patrick

Triple Shot Espresso On The Way!

What is left of our blizzard will exit the nation today leaving in its wake a wide swath of deep snow and shivering citizens. I’ve often contemplated why tropical systems are given names, but not strong extratropical cyclones that form blizzards on the mainland. I suppose too much ‘naming’ can be confusing, but we shall call this last system “Ophelia.” Shakespeare fans will enjoy the reference!

Our Radar Center places the center of circulation over northern Minnesota at the time of this writing with a central pressure of 993MB (use ‘fronts’ overlay checkbox on right) and medium strength snows flanking the western edge of the low. Rain extends from the Great Lakes states into the deep south amidst a mishmash of airmass interactions, however many areas of the south can certainly use the precipitation to aid in refilling their reservoirs.

Last Friday we mentioned the next system that is forecast to develop, our “Roswell low.” This morning examining our various products it appears that we may be in for a Triple Shot, perhaps a caramel mocha latte.

  Main Animations Used In Discussion – Click For Full Size
3.5 Day Forecast Precipitation Type Animation7.5 Day Forecast Precipitation Type Animation
3.5 Day Precipitation Type Animation7.5 Day Precipitation Type Animation

Upcoming Systems

Let’s begin as usual with our 3.5 day Forecast Precipitation Type Animation, then compare that to our 7.5 day product.

The initial frames of the animation show Ophelia slinking through northern Minnesota and into Canada with snows lingering in the northern tier through this evening. The rains we briefly discussed above also continue through the Midwest, south and begin entering the eastern states as evening approaches, with the usual precipitation in the PNW and northern Rockies as well.

Now let’s move along to our ‘Roswell Low’ who for the time being I shall christen “Bubba.” Advance along to F042hr valid 8pm EDT on Thursday. Notice the strong pressure gradient we mentioned during previous discussions build as the frames advance. Hefty winds will sling about Colorado and northern New Mexico as this occurs, with the associated snows. At this frame, notice that Bubba is centered around Santa Fe, and at the next frame F045hr 11pm EDT on Thursday, just north of Roswell. Now here is why I call the Low “Bubba.”

Our discussion on Monday showed that Bubba would swing up towards Chicago and deepen to a respectably low central pressure of 980mb, but our shorter range product disagrees with this morning’s 06z run. Advance along a few frames and see what I mean.

Notice how he slides along on a southeasterly course through Texas with snows in the Panhandle through Kansas, with the opportunity for mixed precipitation thrown into the equation, then beings swinging in a north-northeasterly direction with a very mild central pressure of 1000mb on our last valid frame of F084hr Valid 2pm EDT on Saturday March 28. Well, let’s compare this scenario with our 7.5 day Forecast Precipitation Type Animation, which will also allow us to examine the “triple threat” scenario that seems to be developing.

Hit “stop” and “forward one” until you reach F072hr valid 2am EDT on Saturday, March 28 where Bubba is centered over southern Missouri, but in this scenario with a lower central pressure of 992mb. I’m tempted to lean more towards the development scenario for our medium range product for this system.

By F084hr valid 2pm Saturday, Bubba is centered basically over Springfield Illinois with a central pressure of 990mb. Note the distribution of snow and rain, it will be interesting to see how it develops. On F096hr valid 2am EDT Sunday morning, he is centered over Michigan @ 989mb, and note again the distribution of snows, but here someone else starts to enter the picture. Look just north of Montana on the borders of Alberta and Saskatchewan!

So beginning on Sunday morning we have another zippy clip building up and driving along the northern tier, forecast to reach the Great Lakes states by 8am EDT next Tuesday Morning (F150hr), then over the last few frames, say F168, F174, adn F190 ending Wednesday afternoon, we see a Panhandle hook trying to form over Texas. It will certainly be interesting to see how this triple threat develops!


Thunderstorms on the Horizon

We’ve also discussed the potential for thunderstorms over the next few days. Using our Advisory Center, you can view Convective Outlooks for Day One (today), Day Two (tomorrow), and Day Three (the day after tomorrow).

The essence of the threat for the next few days revolves around the deep trough that we have discussed recently with the result being a respectable return flow of moisture in the deep south and favorable shear environment.

While at the moment today’s Convective Outlook has been issued at the ‘slight’ category, I can see the potential for an upgrade later today to a moderate risk, as the possibility for long lived supercells and tornadoes are definitely in the cards along a wide swath from San Antonio through western Alabama, with the northern extent running along the Arkansas, Louisiana border through Tupelo, MS, and the southern extent being the Gulf of Mexico.

This threat will exist at least through the next three days for today’s region and slightly east, so if you live in and around these areas, today would be a day to pay attention to your NWS Radio (or buy one if you do not own one – I can recommend this Midland or this search will yield alternatives).

Please be sure to view our Advisory and Radar Centers for the latest updates and developments.

As always stay tuned to your favorite weather outlet, stay informed, and stay safe!

cheers,

–patrick

Quick Update On This Storm, More Tomorrow On the Next One

HAMrad II Ptype With Fronts Valid 8am EDT
Our storm has held up quite well with our forecasts over the last 8 days and is still chugging along oriented over central South Dakota this morning. We still have a cornucopia of blizzard warnings and associated winter storm watches and warnings active for the region today. As we stated in yesterday’s discussion the low will lessen in intensity throughout the day before heading into Canada tomorrow afternoon.

As of the time of this writing there were 11 tornado reports received by the SPC with 8 reports of injuries associated with yesterday’s activity. In Cass County, Nebraska 5 injuries were reported as an outbuilding blew into a car, and three injuries where a tree fell onto a truck. Another fascinating report was from Staplehurst, Nebraska where 4.25″ hail was reported yesterday which is defined as larger than grapefruit sized hail, but just shy of the 4.5″ necessary to be classified as softball sized hail. While quite large, it does not quite reach the 7″ diameter stone from Aurora, Nebraska that fell in June 2003. Something certainly worthy of mention in the national media, but coverage has been very limited from this storm.

To view complete storm reports for yesterday, follow this link that is dated for yesterday in the Storm Reports section of our Severe Weather Center.


The SPC has issued a slight risk in their Convective Outlook category for today, and subsequent days as well that concentrate mostly in the southern states.

For today however, the risk area covers a wide swath from Illinois, through Missouri, Arkansas, eastern Texas, and northern Louisiana.

Today’s concerns revolve primarily around a shortwave that will accelerate through the bottom of the trough over the plains this evening and evolve into the region defined by the risk area. The shortwave and a strong associated low level jet will translate into a very favorable shear environment later this afternoon and this evening. However precipitable water becomes another issue for today, otherwise with the well rounded hodographs defined by the very favorable shear environment, today would have been a moderate risk day.

The SPC calls for wind to be the primary threat but does not rule out the possibility of tornadoes this afternoon as the trough moves through the region.

Day 1 Convective Outlook
SPC Day One Convective Outlook Valid 5am EDT
More on our next developing storm tomorrow, or you may review yesterday’s discussion that covers the basics if you missed it.

Please be sure to view our Advisory and Radar Centers for the latest updates and developments.

As always stay tuned to your favorite weather outlet, stay informed, and stay safe!

cheers,

–patrick

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