Area Forecast Discussion
Issued by NWS Charleston, WV

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FXUS61 KRLX 240750
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
350 AM EDT Wed May 24 2017

.SYNOPSIS...
Upper level low digs into the Tennessee Valley and brings
chances of showers today through Thursday. Unsettled again for
the weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 230 AM Wednesday...

Sfc low pressure system over KY and TN will move north into the
OH Valley through tonight. A series of mid level shortwaves
rotating around the upper low will produce unstable conditions
for showers or storms to develop mainly across southeast OH and
over the eastern mountains.

Abundant cloudiness will keep temperatures in the 70s this
afternoon and into the 50s tonight.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
As of 310 AM Wednesday...

Upper low will be overhead on Thursday with scattered showers
expected. An isolated thunderstorm is not out of the question
with the cold temps aloft, but overall thunder threat is quite
low. Ridging builds into the region by Friday morning and will
briefly dry us out as warmer temperatures return as well.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 345 AM Wednesday...

The pattern is starting to take shape for Memorial Day weekend
and the potential for severe thunderstorms is growing. A
stationary boundary will set up from west to east across the
area and current guidance is indicating several short waves
moving through the zonal flow Saturday and Sunday. Deep
southwesterly return flow from the Gulf of Mexico will bring a
warm and moist airmass into the region.

Both the Euro and GFS indicate a plume of high mid level rates
moving into the area on the zonal westerly flow Saturday
afternoon. BUFkit soundings in the GFS indicate this EML on
Saturday with very high CAPE values on forecast soundings in the
order of 2000 to 2500 J/Kg and 700mb to 500mb lapse rates
around 8C/km. The uncertainty lies on timing of a short wave in
order to break a decent Cap and tap into this unstable air.
Confidence is still rather low due to timing disagreement
between the models with the arrival of the short wave. However,
I think there is at least enough ingredients in place that it
warrants mention here that a severe outbreak is possible. Also,
instability does weaken by Sunday but strong 0-6 km bulk shear
with the passing of a cold front could produce severe storms as
well.

Finally, PWATs will be on the rise this weekend and GEFS
indicates values about 2 standard deviations above normal. With
the potential for thunderstorms and low flash flood guidance
values due to rains today and on Thursday, there will be
potential for flash flooding to occur.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
As of 1245 AM Wednesday...

Radar show areas of rain moving northeast across the tri state
area, and another batch across the northeast mountains. Expect
mostly MVFR conditions with very brief IFR/LIFR along with the
rain.

Bufkit soundings suggest saturation at the lower levels at PKB,
CRW, HTS and BKW by 07-08Z.A low stratus deck is expected to
develop overnight across most sites.

Conditions could improve to VFR/MVFR in the morning by 14Z. But
the environment will remain unsettled through Sunday with the
passage of a low pressure system.


FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...

FORECAST CONFIDENCE: Low.

ALTERNATE SCENARIOS: Timing of rain could vary. May need to be
more aggressive with IFR or LIFR tonight.

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.

DATE                              WED 05/24/17
UTC 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
EDT 1HRLY       02   03   04   05   06   07   08   09   10   11   12   13
CRW CONSISTENCY  L    L    L    L    L    L    L    L    L    L    L    L
HTS CONSISTENCY  L    L    L    L    L    L    L    L    L    L    L    L
BKW CONSISTENCY  L    L    L    L    L    L    L    L    L    L    L    L
EKN CONSISTENCY  L    L    L    L    L    L    L    L    L    L    L    L
PKB CONSISTENCY  L    L    L    L    L    L    L    L    L    L    L    L
CKB CONSISTENCY  L    L    L    L    L    L    L    L    L    L    L    L

AFTER 06Z THURSDAY...
Upper level low keeps IFR chances in play through Thursday night.

&&

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

&&

$$
SYNOPSIS...ARJ/MPK
NEAR TERM...ARJ
SHORT TERM...MPK
LONG TERM...MPK
AVIATION...ARJ


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