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Area forecast discussion 
National Weather Service Des Moines Iowa
524 PM CST Tuesday Mar 3 2015

..updated aviation discussion...

Short term /tonight/...
issued at 326 PM CST Tuesday Mar 3 2015

The jet stream will remain active across Iowa into tonight...and
possibly even strengthen slightly...but any sensible weather
effects will be removed from Iowa to the south and east. Nothing
more than periods of middle and high level cloudiness which may
eventually be enhanced somewhat by lift associated with rockies
short wave ejecting into the flow and MO valley. Otherwise the
main story will be a return to colder temperatures. Initial pressure
trough and wind shift is already through the forecast area...and
trailing true cold front was just entering northwest sections at 21z.
Winds will gust to 30kts or more north into the early evening
hours...but no significant blowing snow issues are anticipated
leading to cancellation of the advisory. Dot plow and Highway cams
are showing little if any blowing snow or restrictions so mention
has been removed from the forecast. Some weak banded snow
showers/squalls have developed upstream into South Dakota and Minnesota...but the
phasing of shallow steep lapse rates and instability with
sufficiently cold temperatures /-12c or less/ in the convective area to
generate showers does not look to be occurring this far south.

Long term /Wednesday through Tuesday/...
issued at 326 PM CST Tuesday Mar 3 2015

A few cold days before warming toward the weekend into early next
week...with overall quiet conditions. Cold air to filter into
the state Wednesday with clearing skies as an area of Arctic high
pressure settles southward into the state for Wednesday night into
Thursday. Should see breezy conditions Wednesday with the cold air advection and
stronger winds aloft. 850 mb temperatures aloft in the teens to around 20
below zero celsius. As high pressure moves overhead late Wednesday
night into Thursday...and clear skies expected. Therefore expect a
chilly night well below average for Wednesday night with much of
the area with snow cover falling below zero again. Thursday
continues to be colder...but with some warming aloft and westerly
flow may see a small warm up compared to Wednesday. Warming trend
then starts Friday into the northwest upper level
flow sets up and 850 mb temperatures warm to near freezing. Jet stream lifts
further north toward early next week...with thermal ridging
building into the County Warning Area. Ec/GFS both warm 850 mb temperatures into the +5c to
+10c range for Monday into Tuesday with westerly low level flow.
This should allow sites to warm well above average...with dry
conditions expected. 40s and 50s look quite possible...with some
southern sites even pushing toward 60.


issued at 520 PM CST Tuesday Mar 3 2015

MVFR stratus will push east over the next couple of hours and give
way to mainly ceilings at or above 12000 feet through the overnight. Clearing
by the morning but may see some stratus b/T 3000-4000 feet develop
late Wednesday morning into the afternoon as mixing develops.
Strong winds continue through much of the taf period.


Dmx watches/warnings/advisories...none.



Short term...small
long term...beerends

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