Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 312055
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
355 PM CDT Tue Mar 31 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 355 PM CDT Tue Mar 31 2015

Thunderstorms just south of the CWFA across the eastern Ozarks will
continue moving southeast this evening.  Still a chance that they
could back build into Reynolds county this afternoon, but any storms
that do affect the area should dissipate by 00Z or shortly
thereafter.  Remainder of the night should be dry under a mostly
clear sky.  Wind will turn back to the southeast across the area
before sunrise which should keep temperatures from falling too
precipitously.  MOS guidance looked reasonable so I followed it
closely.

Carney

.LONG TERM:  (Wednesday through Next Tuesday)
Issued at 355 PM CDT Tue Mar 31 2015

The forecast over this period can be broken down into northwest
(quiet) flow versus southwest (active).

Until late Wednesday afternoon, a northwest flow will prevail
over our region, delivering quiet wx, thanks to dry air with little
in the way of any forcing mechanisms.  Temps following persistence
or slightly above look to be the best way to go...with readings well
into the 70s during the daytime Wednesday.

The upper flow will then back to the W-SW by Wednesday night and
continue until late Friday, signalling a more active wx pattern to
close the work week.  A warm front will buckle northward Wednesday
night, with the timing continuing the slower trend.  Slight chance
PoPs Wed afternoon were backed off more with relative quiet
continuing for much of Wednesday night now.  The leftover convection
from what is expected to have been strong to severe over the Mid-MO
valley into the central Plains is still expected to move into areas
well north and west of STL metro but it will be towards daybreak
Thursday morning.

Thursday`s rain looks to come in two waves, with the first ongoing
Thursday morning, with this either exiting or fading and giving way
by late morning to what should be new thunderstorms late Thursday
afternoon.  The slower frontal timing now means that a larger area
of our CWA--generally near and south of I-70--will be under threat
from this new batch of TSRA, of which some are anticipated to be
strong to severe.  This new round of TSRA will then push thru the
remainder of our region near I-70 and south and east of STL metro
Thursday night.

One final round is still expected on Friday, this time primarily
showers with any thunder shunted well to the south.

Temps will be generally low confidence on Thursday, with the
presence of a strong front and rain, but the timing of it all and
exact placement of the front will be critical.  Went max temps of
70s south of the front, to low 60s to the north.

Northwest upper flow then resumes for the weekend giving us at or
slightly below normal temps with dry wx.

Upper flow then backs again from the southwest by Monday of next
week ushering in a more active period.  Chance PoPs for
thunderstorms back in the forecast with temps returning to above
normal.

TES

&&

.AVIATION:  (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1237 PM CDT Tue Mar 31 2015

Northerly flow and VFR flight conditions are expected to prevail
today and into tonight. There is a chance for isolated
thunderstorms across parts of the eastern Ozarks this afternoon in
the vicinity of a cold front which passed through most of the area
this morning. The storm threat should end by 00Z or shortly
thereafter. VFR flight conditions will continue tonight and into
Wednesday. Wind will become light and variable tonight, then turn
to the south-southeast Wednesday morning. Expect wind to increase
through the morning and become gusty Wednesday afternoon.

Specifics for KSTL:

Northerly flow and VFR flight conditions are expected to prevail
at Lambert into early evening. VFR flight conditions will
continue into Wednesday. Wind will become light and variable
tonight, then turn to the south-southeast Wednesday morning.
Expect wind to increase through the morning and become gusty
Wednesday afternoon.

Carney

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&

$$

WFO LSX




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