Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 02/02/24
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
902 PM CST Thu Feb 1 2024
.UPDATE...
Issued at 901 PM CST Thu Feb 1 2024
A narrow band of very light rain and sprinkles associated with an
area of mid-level convergence and saturation is currently stretching
from portions of central Missouri into southwestern Illinois. Rain
within this band has had greater success reaching the surface
than previously expected per recent surface obs. Therefore, we`ve
increased the mention of rain in our forecast above sprinkles to a
low chance (30%) for light rain across that portion of the CWA.
This band`s presentation on radar is likely still overselling what
is reaching the surface given the wedge of dry air present from
about 700mb to the surface seen in RAP analysis and ACARS
soundings out of KSTL. Guidance indicates that the mid-level
convergence will weaken quickly after midnight, bringing an end to
the rain chances shortly thereafter.
Elmore
&&
.KEY MESSAGES...
Key Messages:
- A cold front moving through tonight will cool us down for the
weekend, though temperatures will remain well above average.
- There is still a potential (40-50%) for rain this weekend
focused mainly from central through southeast Missouri. Amounts
will likely remain under half an inch.
- Next week will start off "cooler" (40s and 50s) and gradually
warm ahead of another chance for rain (40-50%) late next week.
&&
.SHORT TERM... (Through Late Friday Night)
Issued at 230 PM CST Thu Feb 1 2024
Despite the cloud cover, temperatures areawide have quickly climbed,
with some locations in southern Missouri having reached 70 degrees
by noon. For areas that do see 70, enjoy it while it`s here. Tonight`s
cold front is pushing its way south, having passed through Des
Moines, IA and Chicago, IL early this afternoon. It is expected to
enter northeast Missouri by this evening, switching winds from
southwesterly to easterly, and kicking off a modest cooling trend.
Patchy advection fog is possible behind the front overnight,
particularly in areas north of I-70. At the time of writing,
slightly elevated winds and warm ground temperatures are expected
to keep widespread, dense fog at bay.
Low cloud cover behind the cold front will last into Friday,
disallowing most of the region to warm as much as we`ve seen
today. Highs in the low 50s are forecast for portions of northeast
Missouri through southwest Illinois where cloud cover will be
thickest, and highs may climb into the low 60s in central and
southeast Missouri where skies will be clearer.
Jaja
&&
.LONG TERM... (Saturday through Next Thursday)
Issued at 230 PM CST Thu Feb 1 2024
Highly amplified upper level ridging in the central CONUS will slide
east on Friday, eventually being undercut by a deepening upper low
Saturday into Sunday. This low will close off and move through the
Southeast CONUS, drawing ample Gulf moisture to the north as it
travels. This setup will spur the formation of a surface low
pressure system in the southern Plains and widespread rainfall
spanning from the northern Plains to the Gulf of Mexico. The
question over the past several days has been if we`ll see any of
this rain, and the answer has (slowly) become more clear.
Deterministic guidance has begun to converge toward a common
solution for the weekend rain potential. The aforementioned rain
corridor is expected to approach the Missouri from the southwest
before brushing our southwest border (Moniteau through Reynolds
County, MO), pivoting to the south, and exiting the area. The
probability of precipitation in these areas remains similar to
previous forecasts, 40-50%, which is similar to the amount of
ensemble members that depict rain at KFAM. Areas that see rain this
weekend aren`t likely to see substantial amounts, as ensemble
probabilities of greater than half an inch peak in Reynolds County
at 20-50%.
Despite this weekend`s system cooling the region down, there`s still
very high confidence that we`ll remain above average through next
week. Sunday will kick off next week with highs in the 40s and 50s.
Ridging aloft and surface high pressure will allow us to gradually
warm through the early week unimpeded by excessive cloud cover or
precipitation. After the benign early week, there is growing
confidence that system will bring the potential for rain back to the
Mid-Mississippi Valley late next week into next weekend.
Jaja
&&
.AVIATION... (For the 00z TAFs through 00z Friday Evening)
Issued at 519 PM CST Thu Feb 1 2024
A weak cold front will move southward through the region and over
the local terminals overnight, causing winds to become
northeasterly in its wake. Along and behind this front, an area of
low stratus is expected to develop and slowly spread across the
terminals late tonight and early tomorrow morning. Given the dry
air in place across the region currently, I suspect that weather
models may be too pessimistic on the height of this stratus, and
have kept flight conditions MVFR for now. However, I can`t rule
out that ceilings briefly drop to IFR for some local terminals.
Additionally, this dry air does not build confidence in fog
developing as some weather models suggest, so I`ve kept it out of
most TAFs for tonight as of now. The exception is KUIN, where if
fog does develop across the region, it would most likely be around
that terminal. Otherwise, the passage of the front will be dry,
though some local terminals may experience a brief sprinkle this
evening ahead of the front. Conditions are expected to improve
tomorrow morning as any fog that develops dissipates and stratus
lifts.
Elmore
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX