Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston WV
659 PM EST sun Mar 1 2015
cold front crosses late tonight. High pressure brings drier
weather Monday into Monday night. Another warm/cold front combo
Tuesday into Wednesday.
Near term /through Monday/...
areas of precipitation continues along a nearly stationary front along
southeast Ohio...extending southwest into central Kentucky. Abundant
clouds and light rain will prevail through midnight. Then...a cold
front will push later overnight taking most precipitation east of the area
by early Monday morning. Lowered probability of precipitation across the southern Coal
fields until the cold front passes late overnight.
Temperatures remain above freezing at least through midnight over
the higher elevations of our northeast mountains. Therefore...the
threat for freezing rain has diminished and the advisory for
Pocahontas County will be allow to expire at 7 PM.
Previous discussion below...
the widespread precipitation will be cut off for the most part
tonight as a cold front crosses the area. Models do suggest one
last west-east dagger of precipitation behind the front tonight...as one
last trailing upper level short wave trough moves through. Considered
extending the Perry-Morgan advisory for this but there should not be
a freezing rain threat and additional snow amounts should be an inch
Otherwise upslope flow supports snow showers in the mountains
overnight into Monday with up to an inch or so there. Low level
moisture will keep plenty of clouds around Monday...a morning cumulus
process in the morning...mixing up into a stratocu deck that should
start to break up in the afternoon. It should clear further as high
pressure builds into the area at the end.
Used hrrr and then NAM/met for temperatures...a bit sharper baroclinic zone
tonight and a bit lower on highs Monday compared with previous with
temperatures not rising much until after 15z.
Short term /Monday night through Wednesday night/...
a prolonged wet system approaches the forecast area on Tuesday and
ultimately decides to take its time moving through the wild and
wonderful state. The GFS is the most progressive of the bunch
while the Euro and NAM are similar keeping a fire hose pointed at
US for at least 24 hours. This forecast more closely follows the
wetter/slower models. Its Worth mentioning that there is some
uncertainty in the location in which the heaviest rain falls...so
the quantitative precipitation forecast is likely blended over a larger portion of the area than
what will actually happen.
The moisture tap for this system extends all the way back to the
Baja California peninsula...so regardless this will be a rather juicy system
with atmospheric river potential. A 70+ knots southwesterly low level jet develops
enhancing low level moisture advection. All said and done 2 inches
of quantitative precipitation forecast sounds reasonable for most places...this coupled with
snowpack melting in the warmer temperatures that we will
experience will cause a scenario where flooding is a large
Also of concern is the stronger winds in the mountains...depending
on how much snow melt occurs and how thawed and saturated the grounds
are this could be another potential hazard.
Long term /Thursday through Sunday/...
frontal boundary will be east of the area Thursday morning...with
colder air filtering into the region...and any lingering
precipitation changing over to snow. Expecting light accumulations
early Thursday...particularly across the higher terrain counties.
High pressure will then build in behind the departing front...for
continued cool...but dry conditions.
Aviation /23z Sunday through Friday/...
widespread IFR ceilings expected across most of the western sites
including ckb to the north while abundant low level moisture
associated with a nearly stationary frontal boundary remains
across southeast Ohio...and areas of mostly rain move east northeast
across the northern half of our County Warning Area.
MVFR conditions to remain at bkw and ekn...but ekn could see a
reduction in ceilings to IFR after 02z due to incoming precipitation.
Visibilities will improve behind the cold front expected to pass late
overnight tonight. This front rolls through west to east between 06z and
Monday will bring improving conditions with mountain snow showers
ending by late morning...and morning cumulus that will evolve into an
afternoon stratocu deck. These cloud heights will rise...but may
remain below 3kft...but start to break up in The Lowlands in the
afternoon...as high pressure builds into the area from the northwest.
Light S surface flow will become moderate west overnight tonight and
then moderate northwest for Monday.
Forecast confidence and alternate scenarios through 00z Tuesday...
Forecast confidence: medium.
Alternate scenarios: guidance show widespread IFR at most sites
tonight. Conditions could improve earlier than anticipated.
Experimental table of flight category objectively shows consistency
of weather forecast office 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 00 01 02 03 04 05 06 07 08 09 10 11
EST 1hrly 19 20 21 22 23 00 01 02 03 04 05 06
crw consistency l l l l l l l l h h h h
heights consistency M M M M l l l h h h h h
bkw consistency l l l l l l h M l l l l
ekn consistency l l l l l l l l l M M M
pkb consistency h h h h l M M h h h h h
ckb consistency l l l l l l l l h h h h
After 00z Tuesday...
IFR possible in rain showers Tuesday into Wednesday...and perhaps
snow at the end Wednesday night.