Weather Forecast and Severe Weather Outlook for Wednesday, April 6, 2016

The return of snow to the Northern Great Lakes, dry conditions continue to be favorable for critical fire conditions after yesterday’s major fires in Oklahoma and Kansas.

The current surface Analysis

Surface map us

Today’s National Forecast

Weather Forecast map

A low pressure system will move across the Upper Midwest and Great Lakes today, bringing rain and snow to those regions. Farther south, rain and thunderstorms will be possible for much of the Mississippi, Ohio, and Tennessee valleys today. The system will spread rain into the Mid-Atlantic and Northeast tonight, with the potential for snow in northern New England. Any snow across northern New England will change to rain on Thursday as the system pulls warmer air north into the region. Heavy rain is possible Thursday into Thursday night across portions of eastern New England, where 1 to 2 inches of rain is forecast to fall, with locally higher amounts. Widespread rain may linger across Maine into Friday morning before the system pulls away.

In its wake, another round of cold temperatures will invade areas from the Midwest to the Mid-Atlantic and Northeast. Scattered rain and snow showers will persist across the Midwest and Great Lakes on Thursday as colder air moves in, and the same will hold true for the eastern U.S. on Thursday night and Friday. While temperatures will remain 5 to 10 degrees below average today across the East, the colder air mass arriving behind this front will result in temperatures 10 to 20 degrees below average for Thursday and Friday across a wide area from the Midwest to the Mid-Atlantic.

The western U.S. will remain dry today with temperatures 10 to 20 degrees above average. An upper-level low over the eastern Pacific will begin to increase moisture across the Southwest by late on Thursday, resulting in scattered showers and thunderstorms. Showers and thunderstorms will become a little more numerous across the Southwest on Friday as increasing moisture interacts with terrain and a decaying stationary frontal boundary.

Current Model Analysis

6 hour model

A cold high pressure system remains over the Northeast and will keep the east coast relatively dry. Low pressure moving into Minnesota will bring rain and snow to the Great Lakes region with Rain near Chicago and Milwaukee with snow up by Green Bay and along Lake Superior.

Further South, some showers will finally begin to move into Oklahoma along the cold front but those will quickly pull east by this afternoon leaving hot and dry conditions ripe for brush fires again today, though conditions will not be quite as bad as yesterday. As the multiple brush fires showed, conditions like these can be very dangerous.

Over on the Pacific coast, a moisture starved low over the Arizona desert might bring some cloudiness to the area but the strong high pressure over the Northern Rockies will keep conditions relatively dry.

18 hour model

By Wednesday afternoon, the East coast should be generally dry as high pressure continues to hold. Temperatures should warm up a little and continue to melt the snow from this past weekend in the Northeast. High pressure actually dominates much of the country as a high over the Rockies keeps things dry there as well. The lone exception is the Great Lakes and Ohio Valley regions, where a strong low pressure system will continue to generate snow for the Northern Great Lakes and bring heavy rain from near Chicago south along the Mississippi River down into Arkansas and Tennessee.   The south will remain dry and hot during the afternoon while the aforementioned fire conditions prevail.

36 hour model

By early Thursday, High pressure is in complete control of the Western half of the county as a cold front draws gulf moisture up the Eastern seaboard and causes rain from Florida to Maine. Some of this rain will be heavy especially over the Appalachians. Snow may fall or mix with rain in extreme northern areas of New England but most snow will stay north in Canada. Some wrap around snow is possible behind the system throughout the Great Lakes.

Current Severe Weather Outlook

***Critical Fire Weather Update***

Areas that saw large brush fires yesterday are still under very hot and dry conditions today with winds expected to be around 20 MPH.

Fire Weather

Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
Critical 107,658 4,352,680 Oklahoma City, OK…Tulsa, OK…Wichita, KS…Norman, OK…Lawton, OK…

Enhanced low and mid-level northwesterly flow ahead of the shortwave will combine with a tight pressure gradient around the surface low to bring a broad corridor of 15-25 mph winds across Kansas and Oklahoma. Low humidities, in the teens and lower 20s, will combine with these strong winds to support a critical area from Southern Oklahoma up to the Kansas, Colorado, Nebraska border areas.

In the surrounding elevated areas, the strongest winds are expected to remain away from the locations with the lowest humidity totals, though borderline critical conditions could occur on a brief and spotty basis.

Severe Outlook

Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 62,158 9,367,939 Nashville, TN…Atlanta, GA…Birmingham, AL…Montgomery, AL…Huntsville, AL…

***Severe Weather Analysis***

…SUMMARY…

Isolated Damagind winds will be possible across parts of the Tennessee Valley and Deep South in the late afternoon to evening.

***Analysis***

A shortwave impulse over the Upper Midwest will rotate towards the Great Lakes today. The impulse is embedded within a trough that is progressing rapidly across the Central States into the Southeast.  The low pressure system will move from Northern Illinois into Ontario leading a surface trough into Kentucky and Tennessee down into parts of the Deep South by early evening.  A cold front will trail this trough to the west arcing across the Lower Mississippi Valley.

The dry continental air currently in place remains prevalent across the entire region driven by high pressure near the Mid-Atlantic States. A plume of moisture over Louisiana will advect northeastwards and increase dew points into the 50s by late afternoon.  Despite high cloud cover, daytime heating could reach into the 70s across Northern Mississippi and Alabama into Central Tennessee which will help drive convection that could be potentially severe until the late evening.

This Week’s Flood Risk

Flood Risk

Yesterday’s Storm Reports

 

Storm Reports

Robert Millette

Staff Meteorologist

Firsthand Weather