Area Forecast Discussion Issued by NWS Charleston, WV
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 282332
AFDRLX
AREA FORECAST DISCUSSION
National Weather Service Charleston WV
632 PM EST Sun Feb 28 2021
.SYNOPSIS...
Threat of flooding continues tonight with periods of moderate
to heavy rainfall. Drier conditions arrive on Monday in the wake
of a cold front, then persisting through most of the week.
&&
.NEAR TERM /THROUGH MONDAY/...
As of 540 PM Sunday...
The main forecast is on track and only modified POPs slightly to
better represent the current observations and trends. Also, held
a bit more cloud coverage for Monday afternoon as frontal
passage will be more of an anafrontal event.
As of 200 PM Sunday...
A warm front continues to march northward through the area this
afternoon with a plethora of Areal Flood Warnings in place in
response to periods of moderate to heavy rainfall. Local and
regional gages depict a swath of 1.5 to 2 inches has already
fallen along the I-64 corridor from eastern Kentucky into the
western portions of West Virginia, where the bulk of flooding
reports have occurred today. Many roads and highways are already
taking on high water issues in the forecast area, so continue to
heed caution if going out and about today.
An area of renewed precipitation rides in along the boundary and
further enhanced by jet dynamics aloft this evening, prompting
an additional 1 to 3 inches of rain across the area. Given the
overly saturated soil conditions already in place from the past
24 hours, most of the rain (and melting snowpack in the
mountains) will become runoff and hike up water levels of many
creeks, streams, and rivers, already noted by real-time river
gages. The Flood Watch remains in effect through the course of
the overnight period for this reason along with the individual
Areal and River Flood Warnings already in place.
To top it all off, warm air advection and breaks in cloud cover
in the southern extent of the forecast area could prompt a few
thunderstorms to sprout this afternoon along the frontal
boundary. Latest obs in southwest Virginia and southern West
Virginia show temperatures outside of the rain shield have
reached the upper 60s. This trend could continue up into the
Charleston metro area, establishing a local unstable
environment that will have to be monitored this evening when
renewed precipitation ushers in from the Tennessee Valley.
A cold front will drive through the area overnight into Monday
morning, which will provide one last shot, albeit short given
its progressive nature, of rain for the first half of Monday.
The chance for precip will quickly diminish from west to east
after daybreak and finally conclude along the higher terrain,
potentially as a combination of rain and snow showers, by the
afternoon. Lingering low level moisture will keep
stratus/stratocu over much of the area Monday before a
reinforcing cold front drops down along the parent upper level
low overnight Monday into Tuesday.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 200 PM Sunday...
Upper level low pressure swings through the Upper Great Lakes
late Monday afternoon and drives a reinforcing cold front
through the forecast area. This will establish much drier
conditions to take hold through the period and much of the work
week as well.
A weak southern stream system forming on the tail end of the
cold front emerges out of the GoM on Wednesday and grazes the
southern portions of the forecast area with a chance of rain and
snow showers, pending surface temperatures at the time of its
arrival. This feature appears to be fairly progressive, so
showers should be east of the Appalachians by Wednesday
afternoon. This will bring the return of quiet and dry weather
at the break point between the short and long term period.
Northwesterly flow in the wake of the secondary frontal passage
will cause morning temperatures to plummet into the 20s and that
appears to be the trend through the week. Given the flattened
upper level pattern and no signs of strong systems encroaching
the forecast area, very little change to the low level flow is
expected. Therefore, there will likely be very little
fluctuation in daily max/min temperatures through the extended
forecast.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 200 PM Sunday...
Arctic high pressure settles into the area by Thursday,
maintaining dry, but colder weather through the end of the
period. Subfreezing H85 temperatures suggest temperatures will
stay below their climatological norm for the first full week of
March.
Models for the back end of the work week suggest a southern
stream system attempting to reach the Central Appalachians by
Thursday, but upper level longwave troughing will shunt the bulk
of precipitation to our south, with perhaps only very light PoPs
sneaking into our southern zones.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
As of 630 PM Sunday...
Southwesterly flow will turn northwesterly by the early
afternoon associated with frontal passage. Slight moderate flow,
generally around 10KT (slightly higher near the mountains),
should hold steady through the period. Gusts into the upper
teens (slightly stronger near EKN/BKW) will likely persist and
willl likely affect all terminals through the afternoon. The
rain will also be persistent with variable VIS restrictions
dependent upon intensity of rainfall into the morning although
on average MVFR conditions will rule. Brief periods of IFR VIS
may occur with frontal passage late in the morning near
CWR/BKW/EKN. Rain tapers off for most terminals by late morning
with EKN/BKW being the last to endure it up until around the
early afternoon. With the rain ending some cloud coverage will
linger past frontal passage creating an anafrontal event leaving
low clouds into the afternoon although conditions should
improve to VFR by mid afternoon with dry air filtering in.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY...
FORECAST CONFIDENCE: Medium.
ALTERNATE SCENARIOS: Ceilings and visibility likely waver
significantly during periods of moderate to heavy rain through
the overnight hours.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09
EST 1HRLY 17 18 19 20 21 22 23 00 01 02 03 04
CRW CONSISTENCY M H M H H H M M H H H H
HTS CONSISTENCY H H M H H H M M M M M H
BKW CONSISTENCY H H M H M M H H H L M H
EKN CONSISTENCY H H H H H H M H H H H H
PKB CONSISTENCY M M M M M M M M H H M M
CKB CONSISTENCY H M M H H L H H H H H H
AFTER 00Z TUESDAY...
No IFR conditions in the foreseeable future after Monday
afternoon.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Flood Watch through Monday morning for WVZ005>008-013>020-
024>034-039-040-515>526.
OH...Flood Watch through Monday morning for OHZ086-087.
KY...Flood Watch through Monday morning for KYZ101>103-105.
VA...Flood Watch through Monday morning for VAZ003-004.
&&
$$
SYNOPSIS...MEK
NEAR TERM...JZ/MEK
SHORT TERM...MEK
LONG TERM...MEK
AVIATION...JZ