Forecast and Severe Outlook for Wednesday, April 13th

A Severe Thunderstorm Watch continues for Southeastern Texas until 6 AM EDT as Strong to severe thunderstorms spread east.

The current Surface Analysis

 

Surface map us

Today’s National Forecast

Weather Forecast map

A cold front cleared most of the East Coast Tuesday evening and has ushered in slightly cooler conditions for the middle of the week. Surface high pressure has settled in behind this front and sunny to partly cloudy skies will be the rule through the rest of the week for much of the eastern U.S. since the overall weather pattern is not expected to change much.  Overall, a very pleasant week albeit on the cool side.

Numerous showers and thunderstorms are in the forecast near the Gulf Coast through Thursday with a stationary front near the coast along with a weak disturbance aloft. Conditions will be favorable for heavy rainfall along with some strong thunderstorms, especially on Wednesday, with the best concentration from southern Louisiana to the Florida panhandle.  A few inches of rainfall is possible for some areas, and flooding remains a localized concern.  However, less in the way of severe thunderstorm coverage is expected compared to earlier in the week.

Across the western U.S., numerous showers and a few thunderstorms are likely from the Pacific Northwest to the central Rockies for the middle of the week, with the greatest rainfall totals expected from northern California to western Washington as a weakening Pacific storm system makes its way onshore, with snow likely at the highest elevations.

Current Model Analysis

6 hour model

The cold front in the East pulls fully off shore and begins to allow for some breaks in the cloud cover over the East coast. A cold high pressure system continues to shift east from the Great Lakes and that will reduce the temperatures in the Northeast as they struggle to get out of the 40s.

Gulf moisture will continue to produce heavy rains in southern Texas as the squall line currently in place remains under a severe thunderstorm watch box. This heavy rain activity should continue for the next few days in the Gulf Coast region.

Further west, instability remains during the overnight and morning hours over the Rockies, rain and snow showers are expected from New Mexico up through Montana. Another wave of rain moves onshore in the Pacific Northwest bringing rain to the valleys and snow to the mountains in what remains a long line of weak low pressure systems coming on shore.

18 hour model

By Wednesday afternoon, A cold front from the low pressure in Canada will create snow  and rain throughout Idaho and Western Montana before shifting east overnight. Gulf moisture will continue to move onshore in Texas and Louisiana and create tropical downpours for significant rainfall.  Flooding will begin to be a risk in these areas during the week as seen below.

Excessive rainfall

36 hour model

By early Thursday, The remnants of the cold front over the south will continue to produce showers and thunderstorms from Louisiana to Florida and Georgia. While high pressure will dominate most of the country, a cold front from a low in Canada will create some shower activity in the Dakotas while a Low pressure system moves onshore in the Pacific Northwest bringing heavy rain to the coastline with snow in the mountains.

Current Severe Weather Outlook

Fire Weather Update

Fire Weather

Severe Outlook

***Severe Weather Analysis***

…SUMMARY…

Severe storms are not expected today.

***Analysis***

Convection across South Central Texas will continue toward the coastline and eventually spread across Southern Louisiana and the Gulf of Mexico later this morning. Any lingering severe threat after tonight will likely be offshore over gulf waters, where a better combination of instability and shear profiles exist.  Destabilization over land is expected to be weak at this time and when combined with weak low level flow, the severe threat over Louisiana appears very limited

This Week’s Flood Risk

Flood Risk

Yesterday’s Storm Reports

Storm Reports

Robert Millette

Staff Meteorologist

Firsthand Weather