Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/11/24
Area Forecast Discussion
National Weather Service La Crosse WI
642 PM CDT Sun Mar 10 2024
.KEY MESSAGES...
- Anomalous, Record Breaking Warmth Into Midweek
- Very Dry Conditions Continue Through Monday, With Increased
Winds Possible In Spots
- Precipitation Potential Returns Late Week, Further Chances
Through The Weekend
&&
.DISCUSSION...
Issued at 150 PM CDT Sun Mar 10 2024
Anomalously Warm & Dry Resulting In Very Dry RHs Through
Monday:
The warming trend of late continues through the new work week, as
daytime highs 5-10 degrees above normal today reach 10-20
degrees normal in spots for Monday. The anticyclonic flow that
passed over the area today ushers in return flow tonight,
advecting the 20 degree isodrosotherm from southwest to
northeast tonight, reaching 30 degrees Monday morning. Timing of
best moisture transport tonight will abate initial sub 25% RHs
west of the Mississippi River early Monday morning. Timing
difference of return flow potentially ceasing late tonight with
meager low level trough differentiates moisture between models
through Monday morning. A weaker, more northerly solution for
the low level trough and tightened pressure gradient allows
farther north advection of the increased low level theta e lobe
and attendant moisture. A farther south solution shunts the
southwesterly winds and attendant better moisture.
As a result, high resolution guidance (10.12Z) differentiates
surface dewpoint temperatures by 10 degrees. A minima in the
ARW keeps the 30 degree isodrosotherm bifurcating the southern
half of the forecast area as westerly winds quickly traverse
from west to east through Monday morning. The result is RHs from
10 to 20% through much of Monday primarily west of the
Mississippi River. Therefore, monitoring factor for very dry
conditions through Monday will be location of low level trough
overnight tonight and resultant low level winds through Monday
morning.
Increased Winds Overnight Through Monday:
Otherwise, increased wind gusts continue to be a lingering forecast
concern into Monday morning. Mixing heights remain in question as
opposing forces of winds and temperatures wage combat. A 40 kt
low level jet streak will support deeper mixing, as well as
higher winds to tap into. Although, clear skies providing
increased boundary layer separation and an off deck warm nose
temperature inversion act to inhibit any mixing. High resolution
guidance again varies greatly as the 10.12Z ARW exhibits an
HREF maxima of 40 mph and to the HRRR (10.12Z) minima of 25 mph
at the same time. Should be noted, ARW (10.12Z) soundings
exhibit the aforementioned PBL separation, wholly preventing
mixing into the off deck winds, peculiar. Have utilized a short
term model blend, removing the higher biases as well as the NBM
overnight high wind biases.
Record Breaking Temperatures Likely For Monday:
Irregardless, the temporary hiatus from peak low level warm air
advection on Monday morning ceases as the low level trough
departs later Monday. Subsequent heights again build and return
return flow. Exit timing of associated low level trough, overlap
of peak diurnal heating, and magnitude of low level heights are
varying solutions forecasted daytime high temperatures Monday
afternoon. Most notable difference between high resolution
(10.12Z) model guidance is location of 70 degree isotherm
relative to the local forecast area. Colder solution keeps 70
degree isotherm well to the south and west in western Iowa
whilst warmer solution grazes same isotherm west of the
Mississippi for a time. Given the lower solutions in the non
bias-corrected high resolution guidance and the persistently
overachieving pattern, have opted with 75h percentile
temperatures, placing much of the area in 70 degree daytime
highs. A gradient in temperatures is expected however, as
eastward extent of strongest warm air advection best coincides
with peak diurnal heating.
Potential For Record Breaking Warmth Continues Through Midweek:
The low level increased low level theta e lobe eventually bears full
aim on the Upper Mississippi River Valley through midweek from
strengthening synoptic return flow and a weak open wave
bolstering southwesterly flow. Similar to previous forecasts and
aforementioned model biases, have increased daytime high
temperatures off of National Blend on Tuesday into the
percentile. Highest long term global ensemble (GEFS/EPS 10.12Z)
confidence (100%) places temperatures near and in the 60s across
the Upper Mississippi River Valley. Eventually, a more active
pattern for the latter half of the week with the low responsible
for the strong mid week WAA passing through northern Wisconsin
remove the record breaking high temperatures. Although, long
term global model ensemble (GEFS/EPS 10.12Z) confidence suggests
5 to 10 degrees above normal sustaining through the weekend.
Precipitation Chances Through The Week & Weekend:
Precipitation chances return Wednesday night as the surface low
responsible for the strongest warm air advection traverses the
Great Lakes and the upper level pattern shifts. Enhanced jet
streaks at 200-350 mb (EPS/GEFS mean) shunt the area of higher
heights south, providing increased upper level forcing locally
within the entrance and exit regions of dual jet streaks. The
upstream trough amplifies deeply before becoming closed over the
Desert Southwest and potentially regressing. As a result, a
similar setup to last week unfolds locally. A surface low and
frontal boundary estranged from the Central Plains through the
Upper Mississippi River Valley provides precipitation chances
(rain) bifurcating the southern half of the forecast area.
Eventually, while the closed, nearly-cutoff upper level low
stagnates over the Desert Southwest, a subsequent digging trough
progresses southern Canada and provides precipitation chances
primarily along our northern half in Wisconsin through the
weekend.
Precipitation Confidence This Week & Weekend:
Confidence in precipitation between ensembles remains moderate to
high for midweek into Thursday, and low to moderate into the
weekend. Initial differences in location of the surface low
midweek resulting in differences for northern extent of
precipitation into Thursday morning. Irregardless, probability
for >0.01"+ of QPF in 24 hours pushes 80- 00% in our southern
half through Thursday and 50-90% for 0.1"+ during the same
window. Confidence has increased to 100% in both the GEFS & EPS
for 0.01"+ 24-hour QPF during this time over the last couple of
runs in a short window in Wisconsin. Otherwise, 50-80%
confidence broad brushes the area into the weekend. Given lower
temperatures, precipitation type will be an upcoming forecast
specific.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 642 PM CDT Sun Mar 10 2024
VFR conditions are expected to continue through the TAF period
with a few passing high clouds. Low level wind shear may
develop for a short period overnight. Right now conditions
appear to be marginal so have held off on the mention (at
KRST/KLSE) and will continue to monitor trends and observations.
&&
.FIRE WEATHER...
Issued at 228 PM CDT Sun Mar 10 2024
Very dry conditions (min RH near 20%) will continue through the
rest of this afternoon into this evening, with winds remaining
light as they become southwesterly. Not expecting much RH recovery
tonight, with RH values around the low 80s west of the Mississippi
with low to mid 70s for RH east of the river. Warm air advecting
into the region overnight will build a decent low-level inversion
that will bring uncertainly to wind gust potential on Monday.
For Monday, the strongest wind potential will be in the morning
with winds around 10 to 15 mph from the WSW, with gusts around
20mph. High temperatures are expected to climb into the mid 60s
to low 70s across the region, though low to mid 60s expected in
central Wisconsin. Dewpoints are expected to slowly increase
through the day, but with high temperatures pushing well-above
normal there is still a good chance at minimum RH values falling
into the 20-25% range west of the river, with min RHs near 30
percent east of the river. Will need to monitor moisture return
and dewpoints through the day on Monday as well as wind speeds
for the potential of elevated fire weather conditions.
&&
.CLIMATE...
Issued at 228 PM CDT Sun Mar 10 2024
The following are record high temperatures at La Crosse and
Rochester for early this week along with the current forecast.
Monday has the highest probabilities of seeing record high
temperatures set with nearly a 100% chance of exceedance at
Rochester and roughly 77% chance at La Crosse. On Tuesday, these
chances decrease with a 59% chance at Rochester and only a 12%
chance at La Crosse.
Monday Tuesday
Location Forecast / Record Forecast / Record
-----------------------------------------------------------
La Crosse 71 / 67 (2012) 72 / 74 (1990)
Rochester 70 / 63 (2012) 69 / 67 (1990)
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...JAR
AVIATION...EMS
FIRE WEATHER...JAW
CLIMATE...Skow/JAW
Area Forecast Discussion
National Weather Service Grand Rapids MI
1006 PM EDT Sun Mar 10 2024
.KEY MESSAGES...
- Decreasing Clouds Tonight
- Warm Air Advection Starts Monday
- Clouds Increase Tuesday
- Multiple Rain Chances Mid to Late Week
&&
.UPDATE...
Issued at 1006 PM EDT Sun Mar 10 2024
No changes from the previous discussion.
&&
.DISCUSSION...
Issued at 210 PM EDT Sun Mar 10 2024
- Decreasing Clouds Tonight
An 850 mb ridge in MN builds east southeast tonight and into the
CWA. Subsidence associated with this feature leads to rapid drying
in the cloud layer. As a result Southwest Lower MI will see
clearing skies late this afternoon and into the evening. The
winds will also be on the decrease. As a result, the radiational
cooling will improve as the night progresses. We are still looking
at low temperatures falling into the mid to upper 20s for most
locations, although the HRRR continues to suggest the GRR area
will not drop into the 20`s.
- Warm Air Advection Starts Monday
Warm air advection develops Monday. We will have the watch the
cloud cover though as forecast soundings are suggesting we may see
some clouds accompanying the onset of the moderating airmass. An
increase in omega is seen at around 850 mb as the RH`s are on the
increase during the afternoon. For now we will keep the skies at
mostly clear for Monday as it is uncertain whether we will
saturate at this level then. Ensemble max temperature forecasts
are supporting high temperatures in the 50s for Monday with not a
lot of spread.
- Clouds Increase Tuesday
Compared to Monday`s ample sunshine, Tuesday will feature increasing
clouds. Model soundings and RH forecasts show mid and upper-level
moisture increasing Tuesday as we enter southwest flow on the back
side of the ridge. Tuesday into Wednesday features our warmest
temperatures of the week as the ridging and southwest flow cause
850mb temps to rise into the 6C-8C range. At the surface this brings
temps in the 60s, well above normal for this time of year.
- Multiple Rain Chances Mid to Late Week
The first chance of rain is low, with PoPs in the 10-30 percent
range Tuesday night into Wednesday morning as a weak cold front
sinks across the area before stalling as a stationary front in Ohio.
While there will be a weak wave in the predominantly zonal flow, low
level moisture is low precluding better rain chances. Rain chances
increase Thursday as a low pressure system moves through the Ohio
Valley along the stationary front. There is some uncertainty as to
the low`s track, with the GFS both farther north with the low/front
and faster than the ECMWF. This takes precipitation further north
and increases amounts of the GFS solution verifies. Regardless, rain
showers are likely in the Thursday into Friday timeframe. Ensemble
CAPE and GFS forecasts show low MUCAPE values near I94 later
Thursday so some thunder can`t be ruled out in this region.
Certainty is lower going into next weekend as there are questions in
the 500mb pattern. The overall pattern features troughing settling
in for the weekend causing temperatures to fall into the 40s by
Sunday. However, the way in which this happens depends on the
strength of a Rex block over the west coast, which cluster analysis
shows well. One possible outcome features a stronger REX block,
forcing the mid-level troughing to dig further south causing
temperatures to fall into the 40s by Saturday, and possibly send a
low through the central Great Lakes. The ECMWF generally shows this
solution. On the other hand, if the block is weaker, the mid level
troughing is more progressive, keeping any potential low further
north and the temps in the 40s away until Sunday, as shown in the
GFS.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 724 PM EDT Sun Mar 10 2024
The back edge of the cu is moving across the Thumb early this
evening and skies are clear across the terminals. Winds will
diminish as the atmosphere decouples and high pressure moves in
during the next few hours.
Clear skies are expected through the period.
&&
.MARINE...
Issued at 1006 PM EDT Sun Mar 10 2024
Gusty northwest winds have weakened and waves heights are slowly
falling. Expect the ongoing Small Craft Advisory to expire by 2AM.
Southwest winds are then expected to build through Monday with
gusts to 25 knots. With these gusty winds, waves are expected to
build once more around 4 feet for areas mainly north of Holland.
Another Small Craft Advisory will likely be needed for the
afternoon and early evening hours.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 2 AM EDT Monday for LMZ844>849.
&&
$$
UPDATE...RAH
DISCUSSION...MJS/Thomas
AVIATION...04
MARINE...RAH
Area Forecast Discussion
National Weather Service North Platte NE
647 PM CDT Sun Mar 10 2024
.KEY MESSAGES...
*Patchy Fog overnight into Monday morning
*Strong winds Monday afternoon across the north
*Critical fire weather Monday afternoon
*Snow potential mid-week
&&
.SHORT TERM /THROUGH MONDAY/...
Issued at 338 PM CDT Sun Mar 10 2024
For the short term the main concerns will be temperatures, fog
and fire weather. Did make adjustments to the afternoon highs
for today and lowered about 5 degrees in some locations across
southwest Nebraska as the deep snow pack has held temperatures
back a little more than expected. Latest visible satellite
imagery continues to show a good swath of snow across southwest
Nebraska, although there has been some melting this afternoon
it has been limited, thus lowered temperatures across snow-
packed locations a few degrees for overnight lows and also kept
them a few degrees cooler for Monday`s highs as well.
As for fog overnight into tomorrow, There will be yet another chance
of fog overnight into the early morning hours. Did add patchy fog to
the forecast, but should mainly be confined along the river valleys.
With the extra low level moisture from the melting snow and winds
generally less than 5 mph would expect patchy, possibly dense at
times, fog to develop, much like it did last night into this
morning. since widespread dense fog conditions is low, will not be
issuing any headlines at this time.
Winds for tomorrow was a little bit tricker of a forecast. Did trend
with the more mixed models as confidence is medium that we should
see good mixing, at least across the northern portions of the CWA
into north central Nebraska, that being said there is the
potential for a layer of cirrus to move in, which could reduce
the amount of mixing tomorrow, but for now cirrus potential is
on the lower end. Looking at forecast soundings winds aloft are
around 25 to 35 kts and would anticipate mixing to the sfc of
at least 25 mph or more for portions of the northern Sandhills
and north central Nebraska. Wind the gusty winds in the
afternoon and drier conditions, min RH values in the teens, did
issue Fire Headlines, check out the fire discussion below for
more details.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Issued at 338 PM CDT Sun Mar 10 2024
The main concern in the long term will be the snow
potential mid-week. A shortwave is expected to move through the
area Wednesday night into Thursday. Do expect the system to have
a decent amount of moisture available, and latest models have
trended up a little on qpf, so would expect to see at least
scattered to widespread precipitation chances. Probabilistic
model members are starting to lead to greater confidence in the
potential to see measurable snow of at least in inch for areas
along and west of HWY 83, so will need to continue to monitor
this system with future forecast. Snowfall is expected to
generally be in the overnight hours as temperatures will be near
to below freezing. Cooler temperatures are expected for Thursday
with highs in the 40s.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 647 PM CDT Sun Mar 10 2024
For KVTN: VFR conditions expected through Monday. Light
southwesterly winds tonight into Monday Morning. Winds near
25013G20KT 18Z until 23Z Monday. Skies FEW250.
For KLBF: Expect VFR conditions this evening. Existing snow
cover and snowmelt has created enhanced boundary level moisture
and some dense fog local to LBF the past 2 nights and there is
a similar signal for fog tonight. Given recent past performance
will lean toward pessimistic solutions and go with a quick trend
to LIFR flight conditions in MIFG, primarily 09Z-13Z. Then VFR
14Z through the end of the TAF period. Winds will be light at or
below 5KT tonight, then light southwest after 14Z Monday.
&&
.FIRE WEATHER...
Issued at 342 PM CDT Sun Mar 10 2024
Critical and near critical fire weather concerns for
Monday afternoon. Did issue a Red Flag Warning for fire weather
zones 209 and 208 where the greatest confidence in RFW criteria
exist. Opted to issue a Fire Weather Watch for zone 204, however the
greatest concern is in the northern portion of the zone, generally
north of HWY 2, the southern portion still has lingering snow pack
and winds will be lighter, do not expect impacts across the southern
zone. The watch may need to be upgraded in future forecast, but at
this time confidence is low given the limited coverage area, and
lower confidence in wind gusts at 25 mph or greater.
Confidence in winds remaining strong Monday afternoon across fire
weather zones 208 and 209, with gust of 25 mph or more is growing.
Probabilistic models show numerous members highlighting an area
generally east of HWY 183 where greater confidence in wind gust
through the afternoon hours will reach 25 mph or possibly
stronger. This mainly falls within fire weather zones 209 and
208 thus a decision was made to upgrade to a RFW. That being
said looking at forecast soundings around VTN and other
locations across portions of 208 and 209, the RAP and SREF are
indicating fairly good mixing, above 700mb which would bring
down some of the stronger winds, which would be around 25 to 30
kts above the 700 mb level giving wind gusts at the sfc greater
than 25mph. The one caveat will be the potential for cirrus to
enter the region, which could hinder/limit some of the daytime
heating and thus could reduce how low the humidity values have
dropped. As for fire weather zone 206 which lies in between the
RFW and the Fire Weather Watch due to the lower confidence, a
decision was made to not include in the RFW or watch, but
conditions will be near-critical Monday afternoon.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch Monday afternoon for NEZ204.
Red Flag Warning from 1 PM to 7 PM CDT Monday for NEZ208-209.
&&
$$
SHORT TERM...Gomez
LONG TERM...Gomez
AVIATION...Roberg
FIRE WEATHER...Gomez
Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
919 PM EDT Sun Mar 10 2024
...New UPDATE...
.UPDATE...
Issued at 914 PM EDT Sun Mar 10 2024
The Wind Advisory will be canceled as obs across the mountains are
showing gusts well under 40 mph, generally between 20-30 mph. A
decreasing trrend is expected to continue through the night as
high pressure continues to build over the area. Some adjustments
to hourly temperatures and dewpoints will be made as well to bring
them in line with obs.
&&
.SHORT TERM...
(This evening through Monday)
Issued at 237 PM EDT Sun Mar 10 2024
Key Messages:
1. Clear and cold tonight with widespread frost.
2. Dry air again Monday afternoon with seasonable temperatures.
Low RH expected.
Discussion:
Northwest flow continues across the area tonight with ridging
beginning to build in from the west. Winds become lighter
overnight with most areas near or below freezing. While we haven`t
begun the frost/freeze program just yet, a widespread freeze is
expected tonight and may impact certain blooming/budding
vegetation.
Low/mid-level ridge axis will be across the Mississippi and
Tennessee Valleys on Monday afternoon with subsidence across the
region. Model guidance has significant spread with expected minRH
values. Surprisingly, the HRRR is on the higher end of guidance
with the global models on the drier side. Have trended towards the
GFS/NBM for Monday Td/RH values because of the synoptic pattern
and because they appear to be handling the dry airmass better
based on surface observations this Sunday afternoon. With winds
near 10 to 20 mph across far NE TN and SW VA, there may be a fire
weather concern that we`ll highlight in the FWF and HWO. Temperatures
will be back near normal with a warming trend heading into mid-
week.
&&
.LONG TERM...
(Monday night through next Sunday)
Issued at 237 PM EDT Sun Mar 10 2024
Key Messages:
1. Warming trend into the work week, with well above normal
temperatures by Thursday.
2. Chances of showers and a few thunderstorms return Friday into the
weekend.
Discussion:
High pressure initially across the southeast will move east this
week with weak ridging aloft. Subsidence will keep conditions dry
this week. A warm trend is expected with temperatures on Tuesday in
the mid to upper 60`s, and in the 70`s by Wednesday. While above
normal, not expecting any record breaking temperatures. A weak
shortwave is expected to move through the Ohio Valley, but it is
moisture starved so not expecting anything from this other than an
increase in cloud cover.
Troughing will develop out west late this week with a closed low
developing across the desert southwest. A surface low developing
across OK/TX will elongate across the Ohio and Mississippi Valley
Friday and into the weekend. Rain chances will increase across the
area beginning mainly Friday into Friday night ahead of a cold
front. Details on the synoptic pattern for the remainder of the
weekend is uncertain as is typical with cutoff lows. NBM holds on to
chance PoPs through Sunday and this seems reasonable given lower
heights to the northwest and moisture still in place. Temperatures
may be slightly cooler this weekend given increased cloud cover and
precipitation expected.
&&
.AVIATION...
(00Z TAFS)
Issued at 702 PM EDT Sun Mar 10 2024
Winds of 10-15 kt, and gusts of 20-25 kt at TRI, will continue
for a few more hours. As high pressure builds in overnight, winds
will become lighter. Clear skies are expected through this period,
with no visibility concerns.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 55 33 62 36 / 0 0 0 0
Knoxville McGhee Tyson Airport, TN 50 30 58 33 / 0 0 0 0
Oak Ridge, TN 53 29 60 32 / 0 0 0 0
Tri Cities Airport, TN 48 27 56 30 / 0 0 0 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SHORT TERM...DGS
LONG TERM....Diegan
AVIATION...DGS