Area Forecast Discussion
Issued by NWS Little Rock, AR

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FXUS64 KLZK 212005

Area Forecast Discussion
National Weather Service Little Rock AR
305 PM CDT Wed Mar 21 2018

.SHORT TERM...Tonight Through Friday

Still seeing the effects of the East Coast storm system this aftn.
Breezy NW winds have been observed, along with some lingering CU ovr
the NE part of AR on the Wrn periphery of the system. Mid aftn temps
have managed to rebound after a chilly start to the day, with
reading in the mid 50s to mid 60s.

Sfc high pressure wl bld into the region tngt, allowing winds to
subside. DO expect to see some high clouds stream acrs the region
from the NW, but still look for another chilly night with lows in
the mid 30s to lower 40s. Cannot rule out some patchy frost in some
sheltered locations, mainly over N/NE AR.

The Sfc high wl quickly shift to the E of AR on Thu, allowing S/SE
winds to return. Heading into Thu ngt and Fri, increasing moisture/
WAA pattern with clouds on the incrs. Model data cont to indicate a
warm fnt wl set up in the VCNTY of NE AR, with small rain chances
mainly to the N of the bndry. Warmer temps wl also return in the
coming days.

.LONG TERM...Friday Night Through Wednesday

Models are starting to show better consensus on how the overall
pattern is going to evolve during the extended term, and at the
moment it`s looking like a scenario involving quite a bit of heavy

I think it would be premature to try and zero in on rainfall amounts
and which area will be impacted the most, but my confidence is
increasing that some part of our area (or perhaps all of it) will
see a significant rain event.

The extended term begins with a rather flat ridge across the area,
with trofs deepening across the eastern seaboard and across the
western US. A swly flow aloft will set up across the area toward the
end of the weekend, and the closed low dropping down across the
southwestern US will start to eject shortwaves across the area. The
models eventually move this low eastward across TX and toward AR by
the end of the week.

In general, the models typically have a difficult time nailing down
the timing of these systems kicking out of the southwest after
they`ve stalled for a while, so I am not going to worry too much
about the timing of the low kicking out just yet, especially since
it`s beyond our forecast period. A lot can change between now and

What does seem likely though is that the system will stall for a
while and eject shortwaves across the area. This will become
problematic because it looks like we will have a quasi-stationary
frontal boundary parked across the region during much of that time.

Sfc progs have a cold front moving thru the area on Saturday into
Saturday night, stalling either across southern AR or northern LA by
Sunday. As cyclogenesis takes place along the leeward side of the
Rockies, a southerly flow will kick in again and the front will
start to return to the north as a warm front. With the newly formed
low sliding to the east, another frontal boundary will drop down
across the area on Wednesday. With a nearly parallel flow aloft,
this boundary will park itself somewhere across the area. Looking
beyond the extended term, it`s quite possible that this boundary may
sit in place for a while.

Tying it all together, this is certainly a concern for heavy rain
and river flooding, and possibly flash flooding as well. The ECMWF
and GFS seem to be favoring the heaviest rainfall axis over portions
of AR, while the Canadian model is focusing more on eastern OK. The
models certainly haven`t come to a consensus on this yet, so I
imagine it will be a few days before we have enough confidence to
start zeroing in on a particular area.

.LZK Watches/Warnings/Advisories...NONE.


Short Term...44 / Long Term...53 is the U.S. government's official web portal to all federal, state and local government web resources and services.