Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/06/21

Area Forecast Discussion

National Weather Service La Crosse WI

 527 PM CST Fri Mar 5 2021

.SHORT TERM...(This evening through Saturday)
Issued at 210 PM CST Fri Mar 5 2021

A continuation of the quiet weather pattern will occur through
Saturday. As the upper level low over the lower Mississippi River
Valley moves east, the upper level ridge over the Rockies will
slowly edge east. This will allow for heights to creep upward over
the Upper Midwest with a large area of surface high pressure
covering the region. The remaining cloud cover over the area this
afternoon will slip to the south allowing for mostly clear skies
overnight and plenty of sunshine Saturday. High temperatures
Saturday are expected to be at or above the 75th percentile of model
solutions with widespread 40s and a few spots hitting 50.

.LONG TERM...(Saturday night through Friday)
Issued at 210 PM CST Fri Mar 5 2021

Surface high pressure slides off to the east Saturday night with
winds becoming more southerly by Sunday afternoon and a ridge moving
into place aloft. A weak shortwave lifting to the northeast through
northern Minnesota into Ontario may introduce some cloud cover,
mainly to the northern portions of the region. As ridging aloft
dominates over much of the central CONUS, warm conditions continue
through mid week with afternoon temperatures reaching 10 to 20
degrees higher than the seasonable normals. Records across the
region may be tied or even broken early next week. Tuesday is
expected to be the warmest day for the area. As surface lapse rates
steepen by the afternoon, temperatures could easily be overachieved
with the additional compressional heating. NAEFS/ECMWF ENS
standardized anomalies for 850 mb temperatures are near 2 standard
deviations above the climatological mean. Under these favorable
conditions, afternoon high temperatures have been increased closer
to the 75th percentile of the blended model guidance. It is
typical for this time of year as the snowpack continues to
diminish, that surface temperatures typically exceed model
guidance under these favorable conditions. Again, will have to
watch out for cloud cover that would limit the amount of direct
solar heating.

Rain chances increase Tuesday night into Wednesday with plenty of
moisture advecting into the area from the south and a surface warm
front lifting northward trough the region. GEFS plumes and
deterministic model guidance are showing CAPE values in the 50 to
200 J/kg range across the region by Wednesday afternoon. Forecast
soundings are showing a `warm nose` layer around 800 to 700 mb that
would need to be overcome for thunderstorm chances to become
possible, which would be more likely by Wednesday afternoon as lapse
rates steepen. Although, not expecting severe storms. With this
first widespread rainfall across the region this season, this would
wash off some dirt and grime following the decent snow-melting
days and bring that lovely springtime petrichor smell to the air.
As for rainfall amounts, GEFS plumes show mean QPF values across
the region around 0.25" and less with PW values nearing 1.0".

As the proceeding cold front dives through the area on Thursday,
some precipitation chances linger for portions of the region. Some
snow chances mix in for areas to the north as cold air filters into
the region. Temperatures return closer to the seasonable normals by
Friday.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 527 PM CST Fri Mar 5 2021

Pesky area of mid level moisture /700-800 MB/ continues to generate
VFR ceilings across much of the area but RAP trends continue to push
this out of the area this evening leading to mostly clear
conditions. As upper ridging continues to build in, expect some high
clouds to stream through on Friday but overall VFR flight rules can
be expected.

Cooler temperatures this afternoon west of the Mississippi River
could raise fog risk overnight with such light flow and expected
clearing skies so will keep an eye on trends. Far too dry of an
airmass most areas but T/Td spreads lower where clouds have
persisted and bit of snow pack still exists.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&

$$

SHORT TERM...04
LONG TERM...Peters
AVIATION...Shea



Area Forecast Discussion

National Weather Service Marquette MI

 529 PM EST Fri Mar 5 2021

.SHORT TERM...(This evening through Saturday)
Issued at 236 PM EST FRI MAR 5 2021

Current RAP analysis and GOES WV imagery continues to show an upper
level low that has shifted a little bit further east over the
Canadian Maritimes, allowing for a sfc high pressure to hold over
the Upper Great Lakes. With northerly flow still occurring, can`t
completely rule out some flurries across the north, mainly east of
Marquette during the daytime hours and along the Lake Superior
shoreline tonight into early Saturday morning. Drier air has been
moving in and along with continued mixing should be enough to not
have flurries reach the ground. Other than that, similar deal as
yesterday where the south and west will be the most sunshine while
the north and east sees more clouds even though there wasn`t much
this morning from satellite and obs. 850mb temps will fall to around
-12C by Saturday morning and with winds backing slightly to the nnw,
this will bring the chance of some light snow showers across the
north Saturday morning but drier air will work in by the afternoon
and will effectively cut off any lingering snow showers.

Temperature will be similar again as to what they where yesterday,
even with some spots overachieving with lack of cloud cover during
the day. Should get into the 30s U.P wide today with slightly cooler
over the Keweenaw with the northerly flow and upper 30s to near 40
along the WI border. Like yesterday, some interior have exceeded
highs so have bumped highs up a few degrees in spots. Lows tonight
could get chilly over the interior west with some single digits
possible, depending on cloud cover. Elsewhere, lows will be in the
teens. Highs Saturday again will be similar to today with coolest
readings (20s) across the north and warmest readings (30s) across
the south. May be slightly cooler across the north with lake induced
clouds hanging around before gradual clearing by late afternoon.

.LONG TERM...(Saturday night through Friday)
Issued at 242 PM EST FRI MAR 5 2021

Overall, expecting a quiet long term period. Mid-upper level ridging
extending from central Texas up well into Hudson Bay will shift
eastward in the early parts of the period. WAA under southerly flow
will precede a weak shortwave late on Sunday. From there, the ridge
shifts eastward into eastern North America and broadens out,
positioning the Upper Great Lakes in a persistent WAA regime through
mid-week. A stronger system looks to move into the region late
Wednesday into Thursday.

Starting Saturday night, the mid-upper level ridge axis will shift
into the western counties. With a good amount of dry air over the
region, expecting the clear skies to really allow ample longwave
radiation to escape, which will help send overnight lows into the
positive single digits for the interior portions of Upper Michigan.
Some of the traditional cold spots in the western interior may even
dip below zero. The lakeshores should be a little warmer in the low
teens. The dry air will stick around for most of Sunday, with WAA
allowing temps in the west to climb into the mid-40s and the east
into the mid-30s. Additionally, ahead of an approaching shortwave,
LLJ will move into the region, allowing for some stronger winds to
mix down to the surface during the afternoon. Toward the evening
hours, the shortwave will approach from the west and help to flatten
out the mid-upper level ridge. The isentropic forcings ahead of the
surface boundary may be enough to squeak out some light precip
overnight but chances look low given the amount of dry air aloft
that will need to be overcome. Overnight lows Sunday night should be
in the 20s, except possibly some low 30s in the west.

High pressure will build in behind this shortwave, leading to a warm
Monday and Tuesday across the region. In fact, some 50s could be
realized in the west half and south, and even some mid-50s look
possible on Tuesday in the interior west. With a mostly dry column
on Monday, ample sunshine shouldn`t be hard to come by. Tuesday,
skies should gradually fill in, becoming mostly cloudy region-wide
by the overnight hours. Surface daytime dewpoints look to be above
freezing, which could result in a quick reduction to our snowpack
across the region between these two days.

Wednesday, southerly flow is expected to continue as a surface low
develops over the Plains and tracks northeast into Upper Michigan.
Increasing PWATs close to 1" by afternoon with strong theta-e
advection, fgen and dynamic forcings look to result in a moderate to
potentially heavy rainfall event. There`s still some discrepancies
among the guidance in where exactly the low will track and thus,
where the subsequent forcings will support the heavier rain. Colder
air filtering in behind the system should limit how high temps will
&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 528 PM EST FRI MAR 5 2021

VFR conditions will continue at IWD and CMX through the period. SAW
will be VFR most of the period except later tonight into Sat morning
when MVFR lake effect clouds will be there.
&&

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 236 PM EST FRI MAR 5 2021

Winds will remain between 20-30 knots over the east half of the lake
through early Saturday morning. Winds should be subsiding to around
15-20 knots by Saturday afternoon then will switch and come out of
the south by Sunday morning with 15-25 knots by the late afternoon
with some gusts up to 30 knots possible. Winds will subside for
Monday and Tuesday before increasing a bit late Tuesday into
Wednesday. Some freezing spray is possible over the central and
eastern parts of the lake tonight through late Saturday night.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&

$$

SHORT TERM...JH
LONG TERM...JP
AVIATION...07
MARINE...JH




Area Forecast Discussion

National Weather Service Riverton WY

 354 PM MST Fri Mar 5 2021

.SHORT TERM...(This evening through Saturday night)
Issued at 150 PM MST Fri Mar 5 2021

Today will continue to be a gorgeous early spring day across the
region. Some breezy southwest winds will continue this afternoon
across the Casper area, but otherwise, not much to talk about
regarding today or tonight`s forecast. Lows will be similar to the
past few nights with basins radiating out.

Cloud cover will be slightly more dense than previous nights, but
will remain scattered to broken high clouds, which won`t be enough
to prevent radiational cooling in most areas. Clouds continue to
increase through the day Saturday as the next system pushes into the
west. Models continue to weaken this system, thus PoPs and QPF were
significantly decreased from guidance. The HRRR has backed off on
the shortwave completely, keeping any precip to the north of the
region. Went more with the GFS solution which keeps some light
precip across the western mountains, but is not as bullish as the
NAM solution. Timing of the system will bring any precip that does
fall, across the western mountains Saturday afternoon and move out
by later Saturday night. Precip will be confined to the western
mountains and Yellowstone Ntl Park. The Canadian solution brings
precipitation across the southwest, but with the current flow
pattern and the nature of the system, we threw that solution out.

The other concern for tomorrow is the gusty winds across the usual
areas, especially Natrona County. With low RH and near 60 degree
temps, this could lead to some elevated fire weather conditions
across that area. RHs do not look to be critical so will hold off on
any highlights. The winds may be SPS worthy, but will let the mid-
shift make that call.


.LONG TERM...(Sunday through Friday)
Issued at 210 PM MST Fri Mar 5 2021

Weak high pressure builds back over the forecast area Saturday
night into Sunday as the weekend wave moves into the northern
Plains. Moderate southwest flow will prevail for the rest of the
weekend as mean high pressure is over the southern plains and a
trough is along the west coast. Clouds will slowly increase on
Sunday as moisture start moving up from the southwest.
Temperatures should be around normal and winds will be breezy.
Monday will see the trough slowly move eastward and develop over
the Intermountain West and northern Rockies as a lee-side surface
low develop over eastern WY. Winds will increase somewhat and
clouds and moisture will increase over western WY. Models are in
good agreement showing an elongated surface low from western SD
into NE CO and a short wave trough moving from NV into easter ID.
This trough will help in pushing a cold front west to east across
the forecast area from early Tuesday morning into Tuesday. The
western mountains and valleys should see moderate precipitation
(rain turning to snow in the lower elevations, and snow in the
mountains) on Tuesday. Additionally, as the surface low over NE CO
deepens, the cold front will wrap through MT southeastward into
NE WY, helping enhance precipitation around the Bighorn Mountains
and increase NE wind behind the front. With the secondary push
from the norther, upslope conditions are expected to develop
across central WY early Wednesday morning through mid-day,
bringing snow to much of the precipitation-starved area. Moist
unstable NW flow remain for Wednesday. Some model guidance is
showing another weak trough moving southeastward in the northwest
flow Thursday, though the GFS and ECMWF are not capturing the
feature. Have allowed higher NBM PoPs to remain in the forecast.
Cool NNW flow then remains from Thursday into Friday, with high
pressure possible late Friday. Overall, an active pattern from
late Monday through the rest of the week for below normal
temperatures and a good chance of precipitation to the entire
forecast area.

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday)
Issued at 345 PM MST Fri Mar 5 2021

VFR conditions will occur through 00Z Sunday. Breezy conditions will
subside early this evening at KCPR. A system will approach NW WY
Saturday, with clouds increasing over western WY Saturday. Scattered
snow and rain showers are to impact NW WY late Saturday afternoon,
and perhaps bringing some light precipitation to KJAC early Saturday
evening. Ahead of this system, southwest winds will strengthen at
most TAF sites, with gusts 25 to 40 kts likely.

&&

.FIRE WEATHER...
Issued AT 150 PM MST Fri Mar 5 2021

Saturday will be a breezy to windy day across much of the region,
especially during the afternoon. RHs will be low, but not critical,
so we do not plan on issuing a Rangeland Fire Danger statement,
despite the wind and well above normal temperatures. Greatest
elevated fire threat will be across eastern Sweetwater county and
Natrona county during the afternoon. Precipitation chances will
increase tomorrow afternoon across the northwest and western
mountains. Snow/rain amounts look to be minimal with the Saturday
cold front. The next more significant chances of precipitation will
be Tuesday and Wednesday across the region.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...Fisher
LONG TERM...McDonald
AVIATION...McDonald
FIRE WEATHER...Fisher



Area Forecast Discussion

National Weather Service Tulsa OK

 952 PM CST Fri Mar 5 2021

.DISCUSSION...
Skies will continue to clear overnight as the upper system that
resulted in light rain earlier today continues to push off to the
east. Drier low level air advecting into the area from the
northeast may tend to limit fog formation, but areas of fog will
remain possible, especially along and west of Highway 75 in
northeast Oklahoma where the drier air will be late to arrive. The
current forecast is on track, and will just resend the zones to
get rid of some of the temporal wording.

&&

.PREV DISCUSSION... /Issued 533 PM CST Fri Mar 5 2021/

AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Upper wave will continue to shift southeast this evening with
rain showers ending. Skies will begin to clear from north to
south tonight with areas of fog likely developing, given the
light winds expected. Current MAV/MET guidance not too aggressive
with dense fog development, however believe some of latest HRRR
runs probably have a better handle given the situation. Went ahead
and used tempo groups for dense fog/LIFR conditions at eastern
Oklahoma sites where the winds will be the lightest and skies
clear the quickest. Fog forecast will likely continue to be
refined this evening as additional data becomes available.

PREV DISCUSSION... /Issued 225 PM CST Fri Mar 5 2021/

DISCUSSION...
An upper low continues to slowly move southeastward across
southeast Oklahoma this afternoon, with widespread light to
occasionally moderate showers rotating around the upper level
circulation. The bulk of the rain should be south and east of the
area this evening, except for parts of southeast Oklahoma and west
central Arkansas where low POPs will remain through mid evening.

The other issue tonight is the potential for fog development,
especially across northeast Oklahoma, where clearing skies and
light winds settle in after midnight. The majority of the short
term guidance shows a fairly widespread area of reduced
visibilities along and north of I-44, with more sporadic and less
drastic reductions across the remainder of the northern half of
the forecast area. Will not issue a Dense Fog Advisory at this
time but will pass along that potential to later shifts.

Warmer and drier weather will be in the offing for the weekend and
through at least the first half of next week, as upper level
ridging builds into the area. Increased southerly winds and return
to well above normal temperatures will lead to an uptick in the
fire weather conditions. However, the persistent southerly low
level flow will also lead to a steady increase in moisture,
serving to mitigate the overall threat of fire starts to some
extent. Forecast winds during this time frame reflect the NBM 90th
percentile values, given the typical low bias of the NBM
deterministic guidance in windier conditions. Forecast high
temperatures have also been nudged closer to the NBM 50th
percentile values.

Toward the middle to latter part of the week, more uncertainty
enters the forecast, as a slow moving upper level storm system
moves into the western United States and a cold front nears the
area from the north. The upper level flow pattern juxtaposed with
the orientation of the front would support the front being very
slow to move southward, at least until the upper low moves closer
to the region. As such, this forecast will favor a slower frontal
progression and continued high temperatures warmer than the NBM
deterministic guidance through at least Thursday. Specifically on
Thursday, clouds and precipitation will limit the overall warming
potential from what could be realized given the expected low
level wind direction. Shower and thunderstorm potential will
increase notably in the Thursday night into Friday period, with
some threat of heavy rain and possibly severe weather. Those
details are not even close to being ironed out, but it`s something
to watch as we move into next week.

&&

.TSA WATCHES/WARNINGS/ADVISORIES...
OK...None.
AR...None.
&&

$$

SHORT TERM...12
LONG TERM....05