Area Forecast Discussion
Issued by NWS St. Louis, MO
FXUS63 KLSX 271701
AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1101 AM CST FRI NOV 27 2015
.SHORT TERM: (Through Tonight)
Issued at 253 AM CST Fri Nov 27 2015
Focus continues to be precip chances and amounts. Late tonight,
focus turns to winter p-types. No changes to the Flood Watch at this
Cdfnt continues to slowly push swd thru the area early this morning.
Expect this fnt to continue to slowly sink swd and shud be along the
sern CWA boarder around 00z this evening. Mdls are in good agreement
regarding mass fields thru the period. However, there are some
differences regarding how quickly precip will shift swd.
Latest guidance suggests another wave of precip will push nwd into
the area this evening/overnight, which may push precip nwd again.
While some pockets of rain may push further nwd, believe the bulk of
the precip will remain across the srn half or so of the CWA.
Focus shifts to cold temps pushing into the region behind the fnt.
At most sites across the CWA, the max temp has already occurred. Some
areas across ern portions of the CWA may rise a degree or two yet
early this morning. Otherwise, expect temps to fall thru the day.
Temps across the CWA are expected to remain above freezing today,
perhaps not by much. However, freezing temps are expected to filter
into nrn portions of the CWA late tonight. Have continued mention of
FZRA late tonight into Sat morning. Still have not mentioned ice
accum across this area as low chance of occurrence and warm ground
temps shud prevent icing.
.LONG TERM: (Saturday through Thursday)
Issued at 339 AM CST Fri Nov 27 2015
(Saturday through Sunday)
Mdls are in fairly good agreement thru this period. However, the
latest NAM ejects the upper low into the Plains earlier than the
consensus, resulting in a deeper low forming over the area and
cooler temps aloft. This soln has not been accounted for in the
A few changes to the prev forecast were made. First, low level
thermal fields are once again warmer than yesterday. Have therefore
trended min temps for Sat and Sun night warmer. This will eliminate
the threat for FZRA as long as this trend continues. Mdls continue
to bring what appears to be the remnants of Hurricane Sandra into
the area on Sun into Sun night. Have raised PoPs across much of the
area to account for this soln.
(Monday through Thursday)
Mdl consensus now develops a sfc low further NW across the Plains.
This results in sly flow early in the period across the region. The
GEM continues to be an outlier and have once again disregarded this
soln. Have also once again therefore trended temps twd a GFS/ECMWF
compromise. Still appears that all precip will be out of the region
by Tues with the remainder of the forecast being dry.
.AVIATION: (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1031 AM CST Fri Nov 27 2015
Slow moving cold front has finally moved just south of CPS. Light
to moderate intensity rain will continue at the taf sites this
afternoon, then likely shift south of UIN this evening while
becoming light in COU. Do not see much change in the cig heights
remaining around to a little below 1000 feet, except there should
be some improvement in UIN, especially Saturday morning. Northerly
surface winds wil continue through the period.
Specifics for KSTL: Persistent light to moderate intensity rain
will continue through most of the period, possibly finally ending
Saturday afternoon as the cold front shifts further southeastward.
Little change in the cig height is expected, remaining just below
1000 feet. There may be a little improvement in the ceiling
Saturday afternoon. A northerly wind will continue through the
MO...Flood Watch through Saturday morning FOR Crawford MO-Franklin MO-
Iron MO-Jefferson MO-Madison MO-Reynolds MO-St. Charles MO-
St. Francois MO-St. Louis City MO-St. Louis MO-Ste.
Genevieve MO-Washington MO.
Flood Watch through late tonight FOR Audrain MO-Boone MO-
Callaway MO-Cole MO-Gasconade MO-Lincoln MO-Moniteau MO-
Montgomery MO-Osage MO-Warren MO.
IL...Flood Watch through Saturday morning FOR Clinton IL-Madison IL-
Monroe IL-Randolph IL-St. Clair IL-Washington IL.