Area Forecast Discussion
Issued by NWS Charleston, WV

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FXUS61 KRLX 261037
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
637 AM EDT THU MAY 26 2016

.SYNOPSIS...
Weak disturbances aloft in an upper level ridging pattern. Slow moving
convection possible Friday/Saturday. Southeast flow may eventually
increase shower coverage late Sunday or Monday...especially over mountains.

&&

.NEAR TERM /THROUGH TONIGHT/...
630 AM Update...
Shower coverage on the slow increase this morning from low to mid
level forcing. All rainfall rates are pretty low with this
activity...and not seeing any lightning.

Previous Discussion...
The center of the upper level ridge off the Atlantic Coast puts us
on the periphery of that ridge...and prone to waves within the weak
synoptic scale flow aloft. All in all...this is not much of a change
from the previous day...as is the fact there is very little in the
way of surface forcing mechanisms. Still have very little in the way
of flow in the lower levels...as well as surface based
instability...although this may be slightly higher across the CWA
given the slightly higher dewpoints expected. Dewpoints will push
the mid 60s by the afternoon hours...but peak heating will once
again be tempered somewhat by variable cloud cover. The end result
is slight to low chance POPS with low confidence of
thunder...although this was added to the showers for a few hours
this afternoon. SPC day one outlook has the CWA well entrenched in
the area of general thunder...no change from the previous issuance
in terms of our area. No severe weather expected in the near term.

Temperatures continue to creep upwards...with only cosmetic changes
to these for the most part for max temperatures today.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
Very weak flow on Friday...tries to increase just slightly on
Saturday...with no fronts in sight.

As a result...no significant mid level disturbances to latch onto.
Will try to have the higher pops Friday over the central mountains
counties...and forming first...with the differential heating. As
mentioned yesterday... can still picture convection over the
southern mountains late afternoon trying to drift north into
southern coal fields and toward Hts or Crw. So left chance pops
over the southern lowlands well into the warm Friday evening.
Localized/isolated downpours can occur under this slow moving
convection on Friday afternoon and evening with precipitable water
around 1.5 inches.

Forecast model soundings showing more instability Saturday
afternoon...while drier air aloft tries to move northwest into
the mountain counties during Saturday afternoon and evening. So
chance pops just as high in the western lowlands Saturday...when
compared to mountains. Again...isolated downpours Saturday
afternoon and evening...probably western lowlands.

On Sunday we are still looking south and southeast. Disturbance
along Carolina coast may increase moisture late Sunday into Monday
and hold down temperatures...especially along eastern slopes.

Temperature wise...forecast a few more 90 degree reading Friday
afternoon if convection holds off until evening for the southern
river valleys like Logan Louisa...Charleston...and Huntington.

At this distance...with weak downslope winds west of the mountains...
we did not lower maximum temperature forecast on Sunday in the western
lowlands as much as...say the 00z Gfs mex guidance suggests.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
Summer like weather will continue during the period as an upper
level ridge remains over the area. Warm afternoons and cool nights
will be the rule. There could be some convection Saturday night
due to afternoon heating and juicy airmass.

The upper level ridge hold until Sunday before drifting off the
east coast. Continue with low chance for the remainder of the
period especially during the afternoons.

A developing tropical system approaches South Carolina by Tuesday
morning. It is a little early to have high confidence on the track
of this system. Will monitor the development and track of this
tropical system.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
Isolated to scattered showers with thunder possible after 16Z
expected today...but the chances do not warrant prevailing
conditions of SHRA at this time. Therefore...the forecast is
VFR through 03Z Friday under cumulus formation in the 4-5kft
range with another mid level deck possible. Chances for late
mist...possibly down to IFR at times...returns. Light surface flow
less than 10kts.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY...

FORECAST CONFIDENCE: Medium to high.

ALTERNATE SCENARIOS: Brief MVFR in a shower is
possible...requiring amendments or short duration TEMPOs.

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       10   11   12   13   14   15   16   17   18   19   20   21
EDT 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
CRW CONSISTENCY  H    M    H    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  M    M    H    H    H    H    H    H    H    H    H    H
PKB CONSISTENCY  M    M    M    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 12Z FRIDAY...
No widespread IFR conditions expected.

&&

.HYDROLOGY...
The river gauge...and forecast point...at the South Side Bridge
in downtown Charleston has not be reading correctly. The NWS
hydrologist is working to correct this problem.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...None.
OH...None.
KY...None.
VA...None.

&&

$$
SYNOPSIS...KTB/26
NEAR TERM...26
SHORT TERM...KTB
LONG TERM...ARJ
AVIATION...26

HYDROLOGY...


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