Area Forecast Discussion
Issued by NWS St. Louis, MO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KLSX 010422
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1122 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 06z TAFs through 06z Wednesday Night)
Issued at 1044 PM CDT Tue Mar 31 2015

Little if any cloud cover expected this forecast period. There
may be a few cirrus clouds, and also a few diurnal cumulus clouds
Wednesday afternoon and early evening. Light surface winds in
surface ridge axis will become s-sely late tonight. The wind will
strengthen and become gusty during the day on Wednesday as the
surface ridge shifts east of the region and a cold front moves
southeastward through the northern Plains causing the surface
pressure gradient to tighten over our area.

Specifics for KSTL: Little if any clouds for much of the period.
There may be a few cirrus clouds, and also a few diurnal cumulus
clouds Wednesday afternoon into the early evening. The light
surface wind will veer around to a sely direction late tonight.
The wind will strengthen and become gusty during the day on
Wednesday. Mid-high level cloudiness will increase late Wednesday
night due to an upper level disturbance and the approaching cold
front.

GKS

&&

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

$$

WFO LSX





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.