Scientific Forecaster Discussion

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Area forecast discussion 
National Weather Service Charleston WV
806 am EDT Friday Apr 18 2014

weak moisture starved cold front moves in Friday night/dissipates.
Storm should remain to our southeast along coast...resulting in dry/warm
Easter weekend. Another front with more available moisture Tuesday.


Near term /through tonight/...
8 am update...updates to hourly temperature and dew point grids. major changes were needed.

Previous discussion follows...
models showing a weak moisture starved cold front pushing into
the region this evening then dissipating. With limited moisture on
all models...will pull probability of precipitation in all but the far northwestern
counties. Even there...will only run slight chance probability of precipitation. With
cirrus clouds tonight and some wind picking up late tonight...will
run toward the warmer mav MOS lows.


Short term /Saturday through Monday night/...
upper low and associated surface low along southeast coast will very slowly
track east into west Atlantic by end of weekend. Sensible weather effects from
this system continues to be mainly a cloud issue...with some cirrus
mainly over southeast WV/SW Virginia zones Saturday. There are hints that some
low level clouds may try to sneak into Pocahontas Sunday night on
some southeast flow 850 mb moisture advection from aforementioned system. Will
start with NE surface flow on Saturday...veering to light southeast flow on
Sunday. For temperatures this weekend tried to roll with warm guidance for
The Lowlands both days with east slopes given a nod on cooler side of
guidance envelope. Tried to incorporate some radiational cooling
effects for overnight lows both nights but with an overall increase
come Sunday night. Fire danger threat will be increasing given low
afternoon relative humidity values and drying of 10 hour fuels...but winds should not
be a complicating factor. All in all...a stellar Easter weekend.

Main change to early next week was to delay probability of precipitation per slower trends
on models for short wave trough and surface front. Have frontal passage on Tuesday with
band of likely probability of precipitation with Monday staying on drier side. Keep thunder
chances in the mountains where best low level instability will
reside. For temperatures Monday...leaned heavily on warmer mex guidance
with upper 70s to around 80f depicted in The Lowlands. Liked idea of
going a bit above even warmest guidance for lows Monday night given
increase in bl stir as well as clouds. Quantitative precipitation forecast wise...this system looks
to carry .25 to .50 inches of rain potential with it. It is getting
on the dry side in the mountains...particularly in the north mountains
with ekn running quite a bit below normal so far this month. So
this would be welcomed rain out there.


Long term /Tuesday through Thursday/...
continued wpc thinking through the long term period. Fairly tranquil
period generally-speaking with the exception of a short wave upper trough
and cold front moving across the area Monday night into Tuesday
morning. Some uncertainty still regarding that system...but yet
better agreement bringing the system across either Monday night or Tuesday
morning. As such...lowered probability of precipitation for much of the daylight hours
Monday before bringing in higher chances of precipitation Monday
night/early Tuesday. Continued to cap precipitation chances at high chance
with the timing uncertainties. No major heat waves or cold blasts on
the horizon during this period. Did warm temperatures up a fair amount for
Monday...into the middle/upper 70s for The Lowlands...with greater
confidence that precipitation won't be affecting the forecast area until
at least Monday night.


Aviation /12z Friday through Tuesday/...
VFR conditions expected through the period despite a weak moisture
starved cold front that moves in this evening and dissipates.

Forecast confidence and alternate scenarios through 12z Saturday...

Forecast confidence: high.

Alternate scenarios: none.

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 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1hrly 07 08 09 10 11 12 13 14 15 16 17 18
crw consistency h h h h h h h h h h h h
heights 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 h h h h h h h h h h h h
pkb consistency h h h 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 Saturday...
no IFR conditions expected.


Rlx watches/warnings/advisories...


near term...rpy/sl
short term...30
long term...50