Tuesday, March 27, 2012

Wednesday, March 28 and Thursday, March 29

Wednesday and Thursday will be warm and dry in the South with some possible thunderstorms in the Southern Plains. Scattered thunderstorms track along the Central Plains along a weak cold front and move into the Ohio Valley and Mid-Atlantic states early Wednesday. This tracking surface low will also bring rain showers to the Northeast and will turn to snow in Maine. Simultaneously, the Pacific Northwest and western Montana will be hit with more rain and mountain snow as an upper-level shortwave trough moves through Wednesday. The real story however, is these abnormally large temperature departures from normal. The reason the Northern to Central Plains are so much warmer than normal is the lack of snow cover. Check out this map of today’s snow cover compared to March 27th last year. What a difference!

After a slight break from the unusually high temperatures we’ve been having in Champaign-Urbana, we are returning to the 70s with a high of 75°F on Wednesday and an overnight low of 47°F as a weak cold front passes through Wednesday evening. Winds will be calming from the WSW becoming NW at 8-22mph. We may also see some isolated thunderstorms possibly becoming severe this evening ending early Wednesday morning. Nevertheless, as soon as the risk of thunderstorms clears out tomorrow we will enjoy mostly sunny skies for the remainder of the day. Thursday temperatures will cool off a bit, but still remain above average with a high of 62°F and a morning low of 41°F. Thursday will be another sunny day with an ENE wind at 8-12mph.

Monday, March 12, 2012

Tuesday, March 13 and Wednesday, March 14

It is getting hot in here! Temperature departures across the continental U.S. are up to 35 degrees above normal with the exception of the West Coast that has temperatures 20 degrees below normal expected for tomorrow. As warm temperatures and sunny skies dominate the central U.S. tomorrow two surface lows located over the Pacific Northwest and above the Great Lakes will stir things up. These wrap- around lows will bring rain to the Pacific Northwest and East Coast tomorrow, but their rather large dry slots will leave portions of both regions dry. This persistent warmth and rain has been a pattern lately and to prove it check out the graphic to the right which shows the number of records across the nation from this past week. Expect more records to come as warm air advection and instability dominate majority of the country into the midweek.

On Tuesday in Champaign-Urbana the warm temperatures are on the rise, so you can ditch that winter coat. Tomorrow will reach a high of 74°F from a morning low of 48°F. Expect sunny skies throughout the day and calm SW winds becoming more southerly at night from 3-10mph. On Wednesday, things will get toasty as temperatures will get very close to 80°F with a daytime high of 78°F and a low only getting down to 53°F. The day will also be full of sunshine with winds from the SSE turning SSW in the evening hours at 6-17mph. Additionally, prepare yourself for Thursday as we gear up from some convection.

Wednesday, March 7, 2012

Thursday, March 8 and Friday, March 9

A long cold front extending from the upper Midwest to the Southwest propagates towards the Midwest and Mississippi Valley tonight bringing rain showers and some thunderstorms with it. This line of storms will shower the East Coast later in the day Thursday and into Friday morning. As this cold front brings storms, behind it follows a very sharp temperature gradient that will drop temperatures up to 30 degrees by early Friday morning! The following graphic depicts just how sharp this temperature gradient is behind this cold front that moves over half the country tonight. On the cold side of the front you see temperatures in the 20s and 30s and on the warm side temperatures are as high as the 60s and 70s with some of these drastic temperature changes occurring across the same state!

For Thursday in Champaign-Urbana we will see a round of rain showers and thunderstorms roll through in the morning hours, but storms should be clearing out by tomorrow afternoon leaving the remainder of the day mostly cloudy. After these storms pass through we are also going to see winds calm and temperatures drop during the day Thursday as this cold front passes over us. The high of 50°F tomorrow will actually occur in the early morning and temperatures will continue to drop to an evening low of 35°F. In regards to the calming winds, we’ll start the day out with a stronger NNW wind that will calm by the evening with speeds ranging form 8-23mph. On Friday temperatures will be cooler, but skies will be sunny and winds will be calmer with a high of 46°F and an early morning low of 27°F with a NNW wind at 8-14mph.

Monday, March 5, 2012

Tuesday, March 6 and Wednesday, March 7

High pressure dominates the eastern portion of the country on Tuesday bringing calm and mostly sunny skies. However, warm air advection from the South will bring warm and windy conditions to the Central Plains, southeastern Midwest and Mississippi Valley. While the conditions remain primarily quiet in the East, a cold front passes over the Pacific Northwest crossing the Northern Plains and Rocky Mountains Tuesday that will bring snow and rain showers behind it. As this cold front slides eastward Wednesday it will showers and strong winds to the Central Plains and Midwest into Wednesday evening. The following graphic depicts the warm air advection that will bring warm and windy conditions to the Central Plains, Midwest and Mississippi for Tuesday.

In Champaign-Urbana on Tuesday temperatures will rise up to 60°F from a morning low of 29 °F as a strong warm SSE wind moving at 14-31mph and gusting up to 39 mph will be accompanied by sunny skies. For Wednesday, warm air doesn’t go anywhere as the daytime high could reach up to 62°F with a low of only 42°F. Windy conditions will persist Wednesday with a SSW at 16-33 mph. During the day Wednesday, skies will be partly cloudy, but clouds will increase as we shift to the evening hours. As the clouds increase Wednesday night we will likely see rain showers and even some possible thunderstorms.

Thursday, March 1, 2012

Thursday, March 1st and Friday, March 2nd

This leap day proved to be a very active one with severe thunderstorms producing deadly tornados in southern Illinois and Missouri leading to severe destruction and 12 reported deaths thus far. The approximately 30 reported tornados flattened through the southern Midwest and Ohio Valley producing an EF4 tornado in Harrisburg, Illinois that left the town in ruins. After this lively Wednesday, Thursday will prove to be a quite day in between storms as a strong low generating in the Southern Plains Thursday will cause widespread severe weather across the southern Midwest, Ohio and Mississippi Valley on Friday. As this low advances northeast toward the Great Lakes late Thursday evening into Friday it will gather moisture from the Gulf of Mexico and strong winds from the West and South producing suitable ingredients for breeding tornados. These severe thunderstorms will also be accompanied by strong winds greater than 55mph and large hail. The NOAA Storm Prediction Center convective outlook graphic to the right depicts the greatest risk of severe thunderstorms having the potential to produce tornados. Areas in this moderate risk should remain cautious and alert of weather conditions throughout the day as tornado watches and warnings will most likely be popping up throughout the day Friday.

After a very blustery day in Champaign-Urbana on Wednesday, however weather conditions will remain calm for Thursday with a high of 51°F and an early morning low dipping down to 32°F. Winds will be calming by the afternoon with a WSW wind become SE at night from 6-21mph. Enjoy Thursday skies as they will be sunny, but as Friday nears another round of severe thunderstorms will be wrecking havoc on the area. Friday will have rain showers and possible severe thunderstorms coming through the area starting Friday morning as a strong low pressure center cuts NE across Illinois. Skies will be overcast to mostly cloudy throughout the day with a high up to 56°F getting down to 34°F in the evening as a cold front moves over us. Winds will be from the S shifting to the W at 10-26mph with stronger wind gusts up to 35mph possible.