000
FXUS63 KLSX 150818
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
318 AM CDT Tue Apr 15 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 314 AM CDT Tue Apr 15 2014

Ongoing Freeze Warning still looks on track to expire at 9am.
Despite the cold start, temperatures should climb into the 40s and
50s today. Initially NW winds expected to briefly become lgt/var
today with the passage of a surface ridge, then turn southerly
around the back side of the high.

Kanofsky

.LONG TERM:  (Tonight through Monday)
Issued at 314 AM CDT Tue Apr 15 2014

Next forecast issue to consider is whether new frost/freeze
headlines are needed for tonight. The surface high will be located
east of the area and wind speeds will be increasing after 06-09z
due to the tightening pressure gradient ahead of a developing
surface low over NE/SD. This means that ideal radiational cooling
conditions will not be present over most of the area. Overnight
lows should be a few degrees warmer than last night (approximately
in the low to mid 30s) with dew points in the low to mid 20s.
Since low-lying areas in the southeastern CWA will probably
decouple early in the evening (under lingering influence of the
departing surface high) and not experience the increased wind
speeds after 06-09z that would interfere with frost formation, a
Frost Advisory looks appropriate for those parts of the
southeastern CWA tonight.

Look for warm and breezy conditions on Wed due to the tightening
pressure gradient ahead of a developing surface low over SD/NE.
Models do not show as much of a secondary low over the OK/TX
panhandles compared to solutions from 24hrs ago, which produces a
different set of solutions for the movement of frontal boundaries
across the central CONUS for Thu-Sat. This variability leads to
continued low confidence in the forecast for Thu-Sat.
Precipitation is possible on Thu night into Fri as a vort max
moves across the region and interacts with moisture being drawn
northward, however one area of model disagreement is exactly how
many vorticity maxima might move across the region during this
time. Models depict another system which could bring precipitation
to the area on Sunday/Sunday night.

Kanofsky

&&

.AVIATION:  (For the 06z TAFs through 06z Tuesday Night)
Issued at 1136 PM CDT Mon Apr 14 2014

Skies have cleared out of taf sites, so clear skies and northwest
winds to persist overnight. Will see some diurnal cu develop by
midday on Tuesday with winds gradually backing to the southwest
then south as surface ridge moves to the east.

Specifics for KSTL:
Skies have cleared out of taf sites, so clear skies and northwest
winds to persist overnight. Will see some diurnal cu develop by
18z Tuesday with winds gradually backing to the southwest then
south by 01z Wednesday as surface ridge moves to the east.

Byrd

&&

.CLIMATE:

RECORD LOWS FOR 4/15:

STL - 27 IN 1928
COU - 25 IN 1928
UIN - 24 IN 1928
FAM - 24 IN 1928


&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...FROST ADVISORY from 1 AM to 9 AM CDT Wednesday FOR Crawford MO-
     Iron MO-Jefferson MO-Madison MO-Reynolds MO-St. Francois MO-
     Ste. Genevieve MO-Washington MO.

     FREEZE WARNING until 9 AM CDT this morning FOR Audrain MO-Boone
     MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
     Iron MO-Jefferson MO-Knox MO-Lewis MO-Lincoln MO-Madison MO-
     Marion MO-Moniteau MO-Monroe MO-Montgomery MO-Osage MO-Pike
     MO-Ralls MO-Reynolds MO-Shelby MO-St. Charles MO-St.
     Francois MO-St. Louis City MO-St. Louis MO-Ste. Genevieve
     MO-Warren MO-Washington MO.

IL...FROST ADVISORY from 1 AM to 9 AM CDT Wednesday FOR Clinton IL-
     Marion IL-Monroe IL-Randolph IL-St. Clair IL-Washington IL.

     FREEZE WARNING until 9 AM CDT this morning FOR Adams IL-Bond IL-
     Brown IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey
     IL-Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL-
     Pike IL-Randolph IL-St. Clair IL-Washington IL.

&&

$$

WFO LSX