Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Wed Apr 12 2023

Valid 12Z Wed Apr 12 2023 - 12Z Fri Apr 14 2023

...Widespread showers and storms with locally heavy rainfall to expand
across the Southeast...

...Unsettled weather shifts into the northern tier of the Intermountain
West, with locally heavy snow for the Northern Rockies...

...Well above average, early summer-like temperatures continue to expand
across the Plains, Midwest, and Northeast...

The forecast remains on track for shower and thunderstorm coverage to
increase along the Central Gulf Coast and Southeast beginning today as
surface low pressure forms along a stationary front in the Gulf of Mexico.
While there still is uncertainty with how this system evolves over the
next 48 hours, more recent models runs depict a broad consensus for a
general northeastward track of this frontal system across the Central Gulf
Coastline. Such a track would favor an initial focused area of heavy
rainfall today generally around southeast Louisiana, coastal Mississippi,
and coastal Alabama, as depicted in the latest WPC rainfall forecast. In
these immediate coastal areas, rainfall totals of 2-4" (locally higher)
could support isolated flash flooding today through Friday. By tomorrow,
the system should migrate inland, spreading widespread showers and
thunderstorms across the Southeast which also could yield isolated flash
floods. Meanwhile, on the eastern fringe of this system, continued daily
thunderstorms within a pattern of easterly onshore flow could exasperate
ongoing localized flooding problems over southeast coastal Florida through
the end of the work week. Scattered flash flooding remains possible today
per the most recent WPC Excessive Rainfall Outlook, where portions of the
Miami Metro are under a Flood Watch through tonight.    

Over the Pacific Northwest, the initial Pacific system responsible for the
repeat rounds of rotten weather earlier this week has finally lifted into
Canada. However, a disturbance close on its heels offshore British
Colombia is forecast to strengthen as it swings through the Pacific
Northwest today. In turn, expect a brief renewal of rain and elevation
snow initially over the Northwest, which shifts into the Northern Rockies
later today into tomorrow. Locally heavy elevation snows can generally be
expected beginning later today across the Bitterroot Range, where 12-18"
of snow are possible in the highest peaks of the Bitterroots, where Winter
Storm Warnings are in effect through midnight tomorrow. Lower elevations
in the Northern High Plains could see a few inches of snow from this event
as well, which could cause minor impacts to travel according to the latest
WPC Winter Storm Severity index.    

Meanwhile, ahead of the wintry weather in the Rockies, well above average,
anomalously warm weather will continue across much of the country as a
potent upper-ridge migrates eastward toward the Central U.S. High
temperatures upwards of 30 to 40 degrees above average will continue today
across portions of the Central Plains through the Upper Midwest as highs
reach into the mid-to upper 80s. Highs will also soar into the upper 70s
and 80s in the Mid-Atlantic today, spreading into the Northeast/New
England on tomorrow. In all, numerous stations across the Plains, Upper
Midwest, and the Northeast could challenge their daily high temperature
records. The warm weather has sparked fire weather concerns across the
Plains, where the Storm Prediction Center now depicts a focused area of
Critical Fire Weather conditions (level 2/3) across north-central Kansas
into Nebraska today, and across southern Colorado through eastern New
Mexico tomorrow. The cold front moving into the Plains will bring
temperatures back to normal later this weekend. 

Asherman/Putnam


Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php