Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/31/24
Area Forecast Discussion
National Weather Service Columbia SC
959 PM EST Tue Jan 30 2024
.SYNOPSIS...
An upper low pressure system will move over the region tonight
and Wednesday with a few showers. Dry weather and slightly
warmer but seasonable temperatures will then continue into the
weekend. Low pressure may develop in the area next Sunday with
cool conditions and precipitation possible into Monday.
&&
.NEAR TERM /UNTIL 7 AM WEDNESDAY MORNING/...
As clearly seen in the water vapor imagery, a sharp digging
mid- upper level trough continues to dive towards the forecast
area this evening. Strong vort advection downstream of the
trough axis is helping pop some scattered showers across eastern
GA and SC, which will continue to slide across the area
overnight. Total QPFs is expected to be low given the low level
dry air that needs to be overcome, and fairly low PWAT`s
overall. Some graupel is an outside possibility especially
towards morning in any of the stronger showers that develop, as
mid-level lapse rates will fall to near dry adiabatic as the
500mb trough axis pushes overhead and surface temps will sit in
the low 40`s; HRRR forecast soundings prog some strong omega
just above the freezing level along with some non-zero MU CAPE
that develops from 700-500mb. The best chance for precip overall
is roughly 11pm through 5am, with showers becoming quite a bit
more isolated after 5am.
&&
.SHORT TERM /7 AM WEDNESDAY MORNING THROUGH FRIDAY/...
Wednesday and Wednesday night...closed upper level low pressure
will be moving over the area through the morning then push off
the coast. The strongest forcing and deeper moisture is expected
to shift to the coast during the mid to late morning hours.
With precipitable water limited, around 0.60 inches in the Pee
Dee, rainfall amounts in the morning should be quite light,
less than 0.10 inch. Cold advection with low-level winds from
the north through the day and with considerable cloudiness,
temperatures may struggle to rise. Adjusted temps down slightly
especially in the north. clearing near AGS so a little warmer
there. Highs expected in low to mid 50s. Pressure ridge building
into the area overnight, and with drier air, expect favorable
radiational cooling. Lows in the low to mid 30s.
Thursday through Friday...Short wave ridging over the area and
surface ridge over the southeast. With warm advection expect
fair weather through the period with temperatures above normal,
especially on Friday.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A backdoor front is expected to drop into the area as a trough
amplifies over New England and the mid Atlantic. A pressure
ridge will build down the east coast into the Carolinas in its
wake. Rex block pattern developing over the weekend as a deep
closed low undercuts a ridge over the Great Lakes/upper
Mississippi Valley. Ensemble guidance has been consistent with
moving the closed low into the northern Gulf of Mexico region
with deepening surface low development to the east across north
Florida to the Ga/SC coastal waters. Highest probability of rain
appears to be Sunday night based on NBM and ensembles. The
ensemble means low position of the coast is further south a bit
than some deterministic guidance like ECMWF. Latest GFS and GEM
have trended drier for Monday. So uncertainty on timing and
details. In addition, strength of CAD uncertain and NBM temp
guidance shows large spread. Went with the cooler side of the
NBM, 25th percentile. It appears to be a weak wedge due to
progressive and weak nature of ridge to the north. Strongest
isentropic lift/upslope flow should be Sunday night at this
time, so highest pops during this period. Drier air moving in by
Tuesday as the low moves further offshore.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions expected through roughly 04z, mix of VFR, MVFR,
and IFR likely from 04z onwards until Wednesday afternoon.
Building strato-cu cloud cover expected through 04z ahead of
some light showers moving in from the west. This showers are
expected to impact the terminals after 04z, likely lingering in
some fashion through 12z. Relatively dry air at the surface will
keep cigs and vsby VFR even in this showers predominantly, with
periodic drops to MVFR in the heavier showers. Following the
bulk of the showers, some lowering cigs and vsby is likely
particularly at CAE and CUB after 10z. Confidence is mixed on
whether or not those sites will fall to IFR or remain low MVFR,
as it is very borderline. For now kept cigs and vsby at MVFR for
this period but updates may be necessary as forecast confidence
improves by the 06z TAF. Cigs will slowly lift to VFR by
Wednesday afternoon for all sites as gusty northwest winds
develop around 7-10 knots, with gusts to near 20 knots.
EXTENDED AVIATION OUTLOOK...Dry air pushing in Wednesday night
is expected to keep conditions VFR through Saturday.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
739 PM CST Tue Jan 30 2024
.KEY MESSAGES...
- Low probability (20-30% chance) for light rain or snow showers
this afternoon and evening.
- Above normal temperatures will prevail through the entire
forecast period...with the warmest days Thursday through
Saturday when high temperatures reach the mid 50s.
&&
.UPDATE...
Issued at 738 PM CST Tue Jan 30 2024
Water vapor imagery shows the upper low has moved into far
southern Indiana. Extensive cloudiness continues over a large
part of the Midwest this evening, which doesn`t look to be going
anywhere anytime soon. Forecasts were updated to boost sky cover
grids to 100% into the first part of Wednesday morning.
A few showers linger across areas east of I-55, a trend which the
latest HRRR suggests will continue the rest of the evening.
Existing forecast already had isolated showers in it, and only
needed some minor adjustments to the placement of PoP`s.
Geelhart
&&
.DISCUSSION...
Issued at 312 PM CST Tue Jan 30 2024
An upper level low remains over the Midwest and Great Lakes, with
an embedded shortwave beginning to traverse the area through this
evening. Scattered sprinkles and perhaps flurries are hinted at by
most high-res models with lift associated with this feature this
afternoon and evening as diurnal heating peaks. Modeled sounding
profiles indicate a capping inversion based around -8 C which
would be close to a maximum limit for ice crystal formation, which
could possibly prevent any precipitation falling as snow, despite
temperatures falling into the mid 30s near and north of I-74 this
evening. Regardless, precipitation amounts should be minimal, and
no accumulation is expected. PoPs are limited to 20-30 percent,
ending from west to east by midnight. Overnight, low cloud cover
should continue across the area, limiting temperature falls, and
lows will struggle to get much below the freezing mark. By
morning, upper level ridging will be building into the region,
with winds shifting to southwesterly, and an associated drier air
mass advecting into the area will help break up some of the cloud
cover through the day, but enough moisture will remain for at
least partly cloudy skies. Modest warming should bring highs into
the mid 40s.
Unfortunately, cloudy skies look to develop again Thursday as a
frontal zone sets up across the area with a surface low in the
central Plains. Weak frontogenesis looks to bring at least a
slight chance of precipitation just to the west, but have kept
PoPs just below mentionable thresholds in most of central IL for
now.
Temperatures look to continue an upward trend Thursday through
Saturday as ridging builds into the Midwest with associated
warming air mass. Highs are forecast to reach the mid 50s.
The next chance for precipitation looks to be over the weekend
when an upper level low emerging from the Southwest U.S. undercuts
the large-scale, high amplitude ridge over the mid-section of the
country. Most current models take this feature through the deep
south, with precipitation remaining south of central IL. However,
ensembles continue to produce a subset of solutions with
precipitation extending north of I-74, and have kept PoPs 20
percent I-74 northward, and as high as 30 percent south of I-74
Sunday into Monday to account for this trajectory uncertainty.
Precipitation amounts look to be relatively inconsequential, with
the ensemble 90th percentile precipitation one half to 0.75 inch,
or in other words, 90% chance of seeing less than that amount.
Relatively mild conditions look to continue in central IL, with
highs continuing in the upper 40s to lower 50s Sunday through
Tuesday, keeping this precipitation rain.
37
&&
.AVIATION... (For the 00z TAFs through 00z Wednesday Evening)
Issued at 522 PM CST Tue Jan 30 2024
A bit of a challenge with evening TAF`s, as regional observations
show pockets of ceilings above 3,000 feet embedded within a more
widespread MVFR ceiling. Midday HREF ensembles show the most
likely periods for VFR conditions would be between 03-10Z,
especially over eastern Illinois. More of an improvement is likely
Wednesday afternoon, as winds shift around to the southwest.
However, KBMI-KDEC east still has probabilities at 60-70% of
ceilings below 3,000 feet late in the afternoon.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Tucson AZ
224 PM MST Tue Jan 30 2024
.SYNOPSIS...Warm temperatures will continue through Thursday with
highs topping out around 6-11 degrees above normal. A passing
weak weather system may bring a few sprinkles to parts of Cochise
County late this afternoon and evening. Then a much stronger
weather system will bring valley rain and mountain snow Thursday
night into Friday with off and on showers lingering into Saturday.
This system will also bring much colder temperatures Friday
onward.
&&
.DISCUSSION...Cloud cover across the area has led to temperatures
running 2-7 degrees below this time yesterday. However expected
highs will still be 5-8 degrees above normal. Moisture has begun
to move into the far southeast portion of the state thanks to a
weak shortwave that will move through northeast Sonora into New
Mexico. Because of this hi-res models show showers/virga
developing late this afternoon into the evening over the eastern
half of Cochise County. Only the HRRR shows a couple showers as
far east as Tucson, but confidence is low in showers making it
that far east. Rain amounts will be very light with these showers.
Wednesday will see continued much higher than normal temperatures
thanks to continued positive height anomalies over southern
Arizona with Tucson seeing a 20 percent chance to hit 80 again.
Positive height anomalies come to an end Thursday as a trough
begins to move into the region. It will have a fairly strong
negative tilt as it moves through along with an associated cold
front that will move move through late Thursday night into Friday
morning. This will bring temperatures 7-12 degrees below normal
Friday into Sunday. This system will also bring anomalous
moisture with GEFS PWAT values around 200 percent of normal just
ahead and along the front. Precip chances begin late Thursday
afternoon in western Pima County and spread eastward to cover the
whole CWA late Thursday night into Friday. Saturday precip chances
decrease from west to east as the moisture exits. Forcing along
the front combined with the upper level support of the trough will
also lead to a slight chance for embedded thunderstorms early
Friday morning. Winds will also be breezy out of the southwest
Thursday and Friday with speeds 15-25 mph.
QPF amounts have decreased some over the last 24 hours, but
current forecast rain amounts range from 0.3"-1.1" in the valleys
and up to 1.5" of liquid in the mountains for the late Thursday
into early Saturday timeframe. Cochise and southeast
Graham/Greenlee Counties will be on the lower end of that range,
Pinal County and northern Graham County will be on the higher
end, and everywhere else in the middle. NBM QPF probabilities for
0.5" or greater range from 40-80 percent everywhere except for the
eastern portion of Cochise County and souther Graham/Greenlee
Counties. Snow levels will initially be 7000-7500 feet Thursday
evening, dropping to 6000 feet Friday afternoon, then 5000 feet
early Saturday morning. Snow amounts have also decreased over the
last 24 hours and now range from 6"-14" above 7000 feet. For now
have opted not to put out any winter weather products due to
uncertainty whether amounts will be at advisory level or warning
level. The bulk of this precip will fall along and just behind the
front, which will be Thursday night into early Friday morning. In
the wake of the front moisture will decrease rapidly, however a
couple weak impulses will follow the main trough. This will lead
to continued light precip chances Friday night with chances
decreasing west to east Saturday morning into the afternoon.
In the wake of the trough ensembles show shortwave troughing over
Arizona Sunday into Monday then another trough impacting the
region by the middle of next week. The ridge will lead to mostly
dry conditions with temperatures warming back to around normal
Monday and Tuesday.
&&
.AVIATION...Valid through 01/00Z.
SCT-BKN clouds AOA 10k ft throughout with ISOLD -SHRA possible
mainly in Cochise County through 31/09Z. SFC winds mainly light
and variable throughout the period with speeds up to 10 kts.
Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Much warmer than normal temperatures will continue
through Thursday before a major change in the weather pattern drives
colder air into the region. A passing weak weather system may bring
a few sprinkles to the area late this afternoon into this evening
otherwise it will be dry through early Thursday. Then a stronger
weather system will bring gusty winds Thursday and valley
rain/mountain snow Thursday night into Friday with some off and on
showers lingering into Saturday. Expect 20 foot wind speeds 15-20
mph Thursday and Friday. After a break in the weather another
storm system looks to impact Arizona early to the middle of the
following week.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
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