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Area forecast discussion 
National Weather Service Des Moines Iowa
323 PM CDT Wednesday Jun 3 2015

Short term /tonight/...
issued at 322 PM CDT Wednesday Jun 3 2015

Tonight...main forecast concern dealt with precipitation/severe weather
chances tonight into Thursday morning or lack thereof as models
continue to trend drier tonight. Forecast area currently within
split flow of upper level vorticity maxes with the 500mb shortwave
exiting the area by 00z Thursday or even sooner.

Currently...weak cold front draped across west-central to north-
central Iowa and there is weak subsidence is in place. Even with
some destabilization occurring over portions of western Iowa...the
frontogenetical forcing is very weak and moisture convergence
remains unimpressive. Might see something develop along the front
through the evening across northern Iowa closer to the low...and
kept small probability of precipitation going in this area. Low confidence with severe
potential due to lack of significant instability and shear present
through the evening.

Otherwise...there is really nothing for storms to focus on
redevelopment until after 06z. The 03.12z models runs have come into
decent agreement with much of Iowa remaining dry through Thursday
morning. The next shortwave looks to eject out of the central
rockies and ride the 500mb ridge tracking generally along the NE/Kansas
border into northwestern MO overnight tonight. Cut back considerably
on probability of precipitation tonight into Thursday morning and even went completely dry
across the north past 06z. The latest hires models...hrrr/hopwrf/arw-
nmmwrf keep the bulk of the convection in western Iowa until 06z.
Kept likely to categorical probability of precipitation going across the far southwest as
higher confidence some of this convection will sneak into this area
b/T 06-12z Thursday. The main threat looks to be heavy rain and
potentially some localized flash flooding. Some isolated areas in
southern Iowa...per radar estimates...received 1-2 inches from this
mornings convection. Precipitable water values remain in the 1.5-2
inch range with good moisture transport into southwest Iowa. Warm
layer cloud depths over 12000 if storms do develop
overnight...some efficient rain producers are likely in the far

Long term /Thursday through Wednesday/...
issued at 322 PM CDT Wednesday Jun 3 2015

Similar challenges to yesterday in extended...with mesoscale systems
providing most of the uncertainty in the synoptic scale pattern
evolution through Friday night. Overall...mesoscale guidance did
well yesterday...along with preference for Euro model over NAM/GFS
which forecast a more northerly extent of mesoscale convective system development last
night and today. By 12z Thursday expecting any leftover convection
to move across western/southern sections with lesser chances over
the north. Nmm/Euro/4 km WRF all suggest that bulk of activity
will be south of the area through the day. Would lean toward
completely rainfree...but some uncertainty still exists so will
leave some chance pop over the west/south for the morning hours
increasing slightly in the afternoon for all locations. Thursday
night may finally bring the front and best focus for heavier
convection farther north. Like today...there is a chance for a few
stronger thunderstorms later Thursday afternoon/evening. Highs
Thursday will once again be dependent on cloud cover...but likely
we may be a few degrees warmer than today. Thursday night the surface
boundary will lift farther north...still modulated by the mesoscale
scale convective systems...with the potential for a round of
moderate to locally heavy rainfall across the south. The exact
details depend on tonights/tomorrows convective trends. For
now...have increased pop over the south. Precipitable
water....warm cloud depths remain high so efficient rainfall
processes will once again need to be monitored through Friday
night. Earlier this morning...northern Missouri saw a few areas
receive 2 to 4 inch totals in a short amount of time. The
persistent trough causing the storms over the plains will remain
in the region through Sunday...however Thursday nights convection
and a high over the Great Lakes will push the boundary south long
enough to bring a break to the rain threat for late Friday evening
through Saturday morning. As another series of waves approaches
from the southwest...another round of thunderstorms is expected
for Saturday night into Sunday. With the eastward progression of a
stronger h500 northern stream wave over southern Canada Sunday...a
ridge of high pressure will settle into the area with less rain
chances Monday through Wednesday as the stronger northern stream
short displaces the trough over the Central Plains. There will be
a chance of thunderstorms over the south. Temperatures through the
period look near to slightly above normal. Highs are expected in
the middle 70s to middle 80s with lows in the lower 60s to upper 60s
with some warming at days 6 and 7.


issued at 1228 PM CDT Wednesday Jun 3 2015

Main concern dealt with MVFR ceilings...or lack thereof this afternoon
and tonight. Iowa is split being two pieces of energy and mainly
leaving cloud cover over the state. Expecting some MVFR ceilings
across northern Iowa through the afternoon at fod/mcw. May affect
alo for a short stint but low confidence in long duration of
these MVFR ceilings and left mention out at this time. Dsm looks to improve to
VFR ceilings past 18z and left out any MVFR ceilings through the
afternoon. Still expecting the potential for overnight into
Thursday morning convection to develop...but with low confidence
in timing and location...left out mention of any MVFR visible/ceilings
at this time.


Dmx watches/warnings/advisories...


Short term...podrazik
long term...rev

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