Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Pittsburgh PA
930 am EDT Monday may 25 2015
shower and thunderstorm chances will increase as the Holiday weekend
draws to a close.
Near term /through tonight/...
changes for the near term period included an upward pop bump...mainly
for the Zanesville and surrounding area...as hrrr has been
persistent in maintaining precipitation with the advancing...albiet weak
shortwave evident on satellite pics. For now...have labeled as
showers given the absence of instability on various model
soundings in response to increasing middle level warmth.
Otherwise...intensifying southwesterly flow will continue to
advect warmth and moisture over the upper Ohio region through
tonight. Changes to an already warm temperature forecast are
Short term /Tuesday through Thursday night/...
continued southwest flow will maintain The Funnel of deep
moisture over the upper Ohio region...at least until middle level
trough axis progression shunts the plume eastward later on
Thursday as per the GFS and NAM solutions.
High end chance...to likely shower and thunderstorm will thus be
maintained for the period. Severe potential still looks to be
compromised by warm middle levels and a marginal deep layer shear
profile...but warm rain processes and training may support locally
No major changes were needed for the seasonably warm temperature
Long term /Friday through Sunday/...
precipitation chances will increase again for the weekend...and persist
into next week as models agree on a weak split flow regime
converging over the Great Lakes/upper Ohio region. The surface
front is projected to sag southward until redeveloping northward
as a warm front in response to Great Plains troughing early next
Given model magnitude...positioning...and timing disputes...persistence
will rule the long term forecast strategy.
Aviation /14z Monday through Friday/...
VFR conditions will continue although high pressure will shift
eastward and support an improving south...to southwest surface
Isolated...to scattered shower and thunderstorm chances will
increase local restriction potential into Tuesday...the better
chance for which will be at zzv and fkl.
Outlook.../Monday through Friday/...
abundant moisture and disturbances in southwest flow are likely
to spawn periodic restrictions through Thursday.