Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/28/24
Area Forecast Discussion
National Weather Service Amarillo TX
654 PM CDT Mon May 27 2024
...New AVIATION...
.SHORT TERM ...
(This evening through Tuesday night)
Issued at 253 PM CDT Mon May 27 2024
Quiet and benign weather continues to hold over the Panhandles
this afternoon as an upper-level ridge build in over the area.
However, do not expect this weather to last much longer as the
lower levels of the atmosphere begin to set up a more active
pattern. To go into further details, to our west a low pressure
system is moving in and expected to stall for the next couple of
days. This low will work in tandem with a high pressure system off
the Gulf Coast to create good southerly flow across the western
Texas and the Panhandles, which will then allow good moisture to
flow into the area. As it stands, latest observations have already
begun to see this expected moisture with dewpoints across the CWA
already on the rise this afternoon. With moisture surging in, the
atmosphere will be primed to showers and thunderstorms for most
of the week with multiple CAMs suggesting we may evening see
activity start as early as tonight.
However, better chances will likely follow tomorrow with the
arrival of a short-wave disturbance for the afternoon. Showers and
thunderstorms are likely to follow with potential to last into the
overnight, but it is the impact where the confidence begins to
wain. As it stands, CAMs are expecting MLCAPE to reach around 2500
to 3000 J/kg with good effective shear present at 30 to 40 kt. The
RAP its self has been very consistent a pocket of 4000 J/kg of
MLCAPE running across the southeast that afternoon as well, which
would indicate the potential for very large hail. However with
PWAT values expected be greater than 1 inch and storm motions
under 25 kt, there is real potential that we see a lot of rain and
concerns shift more to the flooding aspect. Of course there is
also the option of something in between, like getting a lot of
small hail rather than isolated large hail. As for the potential
for tornadoes, currently most model are running on the very low
end of the possibility, but there is some potential present in the
south where 0 to 3 km shear is much better. Regardless, much on
these ingredients will have to be monitor clear into initiation
Tuesday afternoon as they are still able to change, especially if
we do get showers and thunderstorm tonight that last clear into
tomorrow morning.
Scoleri
&&
.LONG TERM ...
(Wednesday through next Sunday)
Issued at 253 PM CDT Mon May 27 2024
Looking ahead to several chances of rain and thunderstorms
throughout a good portion of the Panhandles, with obvious tweaks
to the forecast as we approach each coming day. To start on
Wednesday, leftover elevated showers and thunderstorms from the
previous evening will move east across the eastern Panhandles
throughout the first half of the day. Latest 27/12Z model and
numerical guidance shows a low amplitude ridge impacting general
UL subsidence over the majority of the Panhandles on Wednesday. By
Wednesday night, as the central and northern Plains has aided lift
from a broad area of PVA ejecting out of the central Rockies, the
southern extent of said convection may impact our northern
combined Panhandles with the higher chances being there.
Thursday also looks to be quite an interesting day for strong to
severe convection. Cloud cover, along with more accurate timing
of other mesoscale features will have to be analyzed more closely.
However, a notable H500 neutral tiled trough moving east with its
main axis extending south of the Four Corners Region will place
the best diffluence over the Panhandles for organized lift across
the region. If cloud cover can diminish, along with decent CAPE
values in place, this low shear, high CAPE environment could
suffice for strong to severe thunderstorms. In-conjunction with
large hail and damaging wind gusts with severe storms, PWAT values
are in the 99th percentile for this time of year, so any training
and/or slow moving thunderstorms could produce localized flooding.
With series of perturbations moving east across the Rockies,
diurnally driven showers and thunderstorms will be possible
straight through the coming weekend. Intensity and/or coverage of
thunderstorms will be better analyzed each passing day with
frequent updates. With the exception of the airmass in the wake
of the cold front by Friday with highs below average, the
remainder of the forecast period from Wednesday through the coming
weekend will feature temperatures above average as we approach
the end of May into early June.
Meccariello
&&
.AVIATION...
(00Z TAFS)
Issued at 639 PM CDT Mon May 27 2024
Breezy wind conditions will settle down this evening and calmer
southeasterly flow will remain in place through tomorrow.
Thunderstorm chances are present at all terminal sites in the late
afternoon and evening tomorrow. Confidence has increase enough to
introduce PROB30 groups at the end of the TAF period. VFR
conditions should prevail through this period until thunderstorms
advance onto the TAF sites. Ceilings are then forecast to drop to
MVFR.
Rangel
&&
.PRELIMINARY POINT TEMPS/POPS...
Amarillo TX 61 86 58 76 / 10 50 60 40
Beaver OK 58 83 58 79 / 20 50 70 40
Boise City OK 53 82 55 78 / 20 50 60 50
Borger TX 63 89 61 81 / 10 50 70 40
Boys Ranch TX 61 90 58 82 / 10 50 60 30
Canyon TX 60 88 58 76 / 10 50 60 40
Clarendon TX 62 86 59 75 / 10 60 70 50
Dalhart TX 55 84 54 79 / 10 50 60 40
Guymon OK 56 83 56 79 / 20 50 70 40
Hereford TX 60 91 58 80 / 0 50 50 40
Lipscomb TX 61 82 59 78 / 20 50 70 40
Pampa TX 61 84 59 77 / 10 50 70 40
Shamrock TX 63 83 60 77 / 20 60 70 50
Wellington TX 64 86 61 78 / 20 70 70 60
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...None.
OK...None.
&&
$$
SHORT TERM...11
LONG TERM....29
AVIATION...55
the prior forecast discussions remain valid.
See below for additional information.
735 PM Update:
Radar, lightning and METAR trends show a band of increasingly
steadier and moderate to bursts of heavier rains over Tolland
and Hartford Counties in CT and into adjacent sections of
central and western MA, although in an air mass of very weak
instability, little to no lightning has been observed. Ended up
backing off on the thunder risk in the zone forecast for most
locations tonight with this update and overnight as model
forecasts from the NAM and RAP are pretty sparse on most-
unstable-parcel CAPE. The possible exception comes in around
midnight and overnight into RI and adjacent portions of
southeast MA and the waters where the NAM and RAP show about
600-800 J/kg of most-unstable CAPE. HRRR and the NAM-3km also
show indications for thunder in this general area, and although
we`re not expecting storms to reach severe levels for those
areas, late- night boomers here could still be possible. The
rather humid air mass leading to high warm cloud depths seems
apt to favor downpours in any heavier showers and isolated hydro
issues could still result; the good news is that the showers
are moving along at a decent clip so think anything worse than
isolated instances of flooding are probably going to be hard to
come by, even in the more flood- prone areas. Given the strength
of the SE to S winds tonight, am becoming less convinced on
there being foggy areas for the overnight, and it could be quite
patchy if any develops, even over the waters.
Still going to be rather humid for most of the night with low
temps in the lower to mid 60s, even with the front nearing the
coastline by daybreak.
Previous discussion:
Low pressure continues to track to our north this evening into
southern Canada as associated cold front closes in on southern New
England from the west. Warm sector remains south and west of our
region, which will help mitigate the severe weather threat, but does
not totally limit the convective potential this evening.
Robust convective line has already developed in a NW to SE
orientation form the Syracuse to NYC area which is generally
well depicted in the 12Z NAM Nest, NSSL WRF, and ARW members of
the HREF. This line will continue to lift into the region over
the next several hours, with prefrontal downpours overspreading
SNE between 21-01Z. Convection will struggle to maintain
strength as it pushes east as we lack surface based instability
given our position in the cool sector and very very poor low
level lapse rates between 4.5- 5.5C/km, resulting in mainly
elevated convection that will capitalize on ~600J/kg MUCAPE.
This is good news, as storms will not be able to tap into low
LCLs, below 1000ft, and strong 0-1km shear present across
Upstate NY/PA, significantly curbing any tornado threat as the
front moves east.
Greatest threat with this cold front remains heavy rain with PWATs
climbing to around 2" and high warm cloud depths approaching
12,000ft. Aforementioned conditions combined with a southerly
oriented LLJ of ~40kt will lead to embedded tropical-like
downpours this evening and early overnight. Fortunately, this
front is quite progressive, looking to be offshore by ~07/08Z,
which will mitigate any significant flooding concerns. With that
said, 1-2" of rain over an urban center like Providence or
Springfield could lead to some isolated poor drainage flooding.
Moderately strong jet will be able to mix down in heaviest
downpours, yielding gusts in excess of 25kt along the frontal
boundary tonight.
Residual moisture, with dewpoints still in the upper 50s/low 60s,
and flow veering to the SW behind the front will lead to marine fog
development again overnight. Strong southerly flow, in excess of
10kt, will mitigate the fog threat across the interior, but do
expect some dense fog development overnight along the south coast
and Cape.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
While some stratus and fog will hang on for the first part of the
morning, southerly flow and mid level dry air will begin to scour
out the clouds between 12-15Z, leading to a brighter and warmer day
for much of southern New England! Overnight`s cold front will stall
offshore, and given proximity to the Cape and Islands results in
cloud cover sticking around until at least the early afternoon,
though, not too optimistic that Nantucket will break into sunshine
at all. With SW surface flow and WAA, will see temperatures climb
into the upper 70s and low 80s away from the coast, and with SSTs
approaching 60F, even the south coast looks mild tomorrow, in the
upper 60s!
Trough begins to sag south from Canada tomorrow afternoon which may
initiate some spotty shower and thunderstorms across far northern MA
tomorrow afternoon and evening with ~600J/kg MUCape and low level
lapse rates approaching 8C/km. Shear will definitely be present,
with 0-6km bulk shear exceeding 50KT between 18-00Z, but mid level
lapse rates are quite poor, less that 6C/km as dry air continues to
work into the mid levels. Given this limiting factor, expecting low
topped convection at best that may result in isolated showers and a
few rumbles of thunder. Will note that instability is much higher
across SE MA/RI where temps/dew points will be a few degrees warmer,
with MUCAPE growing in excess of 1000J/kg, but shear and lapse rates
are not colocated with that axis of greatest CAPE. If showers are
even able to develop, they will be mainly north and west of
Worcester/I-495.
Winds shift to the W/NW tomorrow night which will significantly curb
the threat for widespread fog, even with dewpoints in the upper 50s
to near 60F. Cant rule out some Marine fog for the Cape and Islands,
but certainly expect it to be much less widespread than the past few
nights.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Highlights:
* Temps cool off toward more seasonable levels with comfortable
humidity levels Wed thru Fri.
* Stronger indications for rains on Wed night into Thurs, although
soaking rains aren`t expected. Dry weather prevails otherwise.
* Remains dry this weekend into early next week, but with steadily
warming temperatures toward above normal levels.
Details:
The mid to late week period will be governed by a deep upper level
trough associated with a pocket of cooler air aloft (e.g. 850 mb
temps in the mid to upper single digits C range). Most of the first
part of Wednesday looks dry, although rain chances start to increase
later in the day associated with a cold front aloft. Really can`t
see too much in the way of QPF with this late-day activity
(indicated about 20-25% PoP), but the rain risk increases Wed night
into Thurs associated with shortwave trough energy rounding the
periphery of the upper longwave trough. While the Canadian GEM is
still a suppressed/southern outlier, the GFS has now depicted
showers for Wed night into Thurs, as indicated previously by the
ECMWF and its ensembles. There is more uncertainty as it comes to
QPF amts, with the ECMWF remaining quite bullish and the GFS being
lighter. Potential is increasing for at least a steadier light rain
event, but probably not looking at a soaking rain situation. Thus
brought PoPs up into the 40-55% range for now for Wed night into
Thurs. This could still be a bit conservative and could need
adjusting upward in future updates. Otherwise, dry weather prevails
into Friday. Temps in this period cool off to more seasonable levels
with no significant temperature anomalies one way or the other. Wed
looks to be the warmest in the 70s to a few low 80s, with a cooling
trend into the lower to mid 70s for Thurs and Fri, with upper 60s
near the coasts with better chances for seabreezes/onshore flow on
Thurs and Fri.
The deep upper-level trough then moves offshore as we move into the
weekend into early next week, allowing for 500 mb heights to rise
along with warming 925-850 mb temps. Expect generally dry weather in
this forecast period as high pressure over the Gt Lakes moves ESE
into the mid-Atlc waters through the weekend and remain in place
into next Mon. As 500 mb heights start to rise and low-level temps
begin a steady warming trend, expect temps to begin to rise back to
slightly above normal levels with highs in the mid 70s to lower 80s
with tolerable humidity levels (dewpoints in the lower 50s). Overall
outlook for the first weekend in June seems pretty favorable for
outdoor plans with dry weather, seasonable to slightly milder than
normal temps and low humidity levels.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Forecast Confidence Levels:
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
00z TAF Update:
Tonight: Moderate confidence.
Deterioration back to IFR-LIFR levels with a band of steady
moderate to heavy rain spreading in from west to east between
00-06z. See TAFs for specific timing with the period of heaviest
rains delineated with +SHRA. Appears the greatest potential for
TSRA is at PVD and the Cape/ACK airports after 05z, but that
will need to be handled with TEMPOs. Rain generally diminishes
in most areas between 09-12z, though may linger into Tue AM
across a portion of SE MA. SE to S winds around 10-13 kt with
gusts 20-25 kt, and that should be enough to preclude fog
development.
Tuesday... High Confidence. Cold front stalls offshore but will
generally yield VFR conditions after 15Z tomorrow, the
exception being the Cape and Islands, especially ACK, which will
struggle to shake IFR. Brisk SW flow of up to 20kt. Some
isolated low topped thunderstorms possible in northern MA after
21Z tomorrow afternoon.
Tomorrow Night...Generally VFR, though again cant rule out some
marine stratus and fog. Breezy SW flow continues.
KBOS TAF...High confidence in TAF trends, moderate in timing.
MVFR deteriorates to IFR ceilings with a band of moderate to
heavy SHRA after 02z, visbys as low as 2 SM. Thunder is now
viewed as less likely. Rain continues through about 09z but then
shifts offshore; IFR cigs likely to continue until ~13z Tue with
a more rapid return to VFR. SE winds around 10-13 kt before
shifting to SW by early Tue AM.
KBDL TAF...High confidence in TAF trends, moderate in timing.
MVFR/IFR with +SHRA thru about 06z, then rain decreases in
intensity after 06z before trending dry by 08z. Cigs to trend
MVFR by 06-08z with more rapid improvement to VFR by Tue AM.
S winds around 10-12 kt before becoming SW by early Tue AM.
Outlook /Wednesday through Saturday/...
Wednesday through Thursday: VFR. Chance SHRA.
Thursday Night: VFR. Slight chance SHRA.
Friday through Saturday: VFR.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
310 PM Update:
Small craft advisories continue on most waters tonight into Tue,
with SE winds near 25 kt and seas building to around 5 ft.
For tonight, SE winds increase to around 20-25 kt with seas 4-5 ft
offshore and around 2-3 ft nearshore. Winds will shift to SW later
in the overnight as a cold front passes over the waters. Low clouds
and fog could restrict visibility through later this evening. There
is also a risk for thunderstorms capable of lightning and brief
downpours, although severe weather is not expected.
For Tue into Tue night, SW to WSW winds around 15-20 kt are expected
with seas rising to around 5-6 ft on the southern and eastern outer
waters and around 3 ft or less nearshore. Dry weather with good
visibility
Outlook /Wednesday through Saturday/...
Wednesday: Winds less than 25 kt. Areas of seas approaching
5 ft.
Wednesday Night through Thursday: Winds less than 25 kt. Chance
of rain showers.
Thursday Night through Saturday: Winds less than 25 kt.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 11 AM EDT Tuesday for ANZ232-233-
235-237.
Small Craft Advisory until 5 AM EDT Wednesday for ANZ250-
254>256.
&&
$$
SYNOPSIS...Loconto/KS
NEAR TERM...Loconto/Dooley/KS
SHORT TERM...KS
LONG TERM...Loconto
AVIATION...Loconto/KS
MARINE...Loconto/KS
Area Forecast Discussion
National Weather Service Caribou ME
944 PM EDT Mon May 27 2024
.SYNOPSIS...
Low pressure will track to our northwest through Tuesday. Upper
level low pressure will remain over the area Wednesday into
Thursday then slowly lift to the northeast on Friday. High
pressure builds in for the weekend.
&&
.NEAR TERM /THROUGH TUESDAY/...
Update...
Warm front currently to our southwest will slowly lift north
across the region late tonight into early Tuesday morning.
Latest radar reflectivity imagery shows an area of steadier
rainfall lifting northeast from VT and NH. Latest HRRR brings
this through the forecast area after midnight. With increasing
pwats some locally heavy downpours cant be ruled out overnight.
Just minor adjustments to hourly temps/dew points otherwise
forecast remains on track.
previous discussion
By Tuesday, the warm front will move through the region pushing
the rest of the showers off to the east by late morning. High
res models and RH models show a time of brief clearing in the
clouds before the cold front approaches the area. Though the
passage of the warm front will stabilize the area, this clearing
of clouds and sunny afternoon will help destabilize the region
again. The heating of the day and the frontal lift will start
producing thunderstorms in the afternoon. The ingredients are
present according to several upper air soundings for these
storms to create gusty winds and small hail.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
Thunderstorms with the cold front will end quickly in the
evening. The front will stall and fog will reform Downeast in
the humid air south of the front. Lows will drop to the low to
mid 50s.
For Wednesday, the trend was towards decreasing PoPs and clouds.
Nonetheless, sufficient moisture at 850mb in the northerly flow
will promote cu/stratocu fields in the north. The front sags
slowly southward into the Downeast region by afternoon.
Convergence along the front will generate showers and
thunderstorms Downeast, and possibly westward to Bangor. Some
guidance such as GEMS develop a shortwave moving through the
broader upper level trough to generate lift. A fair number of
models develops a narrow band of SBCAPE in the 500 to 1000 J/kg
range. The afternoon starts with sufficient shear to raise the
chance of stronger storms, but shear rapidly diminishes as the
afternoon progresses. Hail would definitely be a consideration
given the low freezing level if models continue to advertise the
stalled front Downeast. Strong winds seem unlikely unless there
is a particularly strong cell.
The front exits offshore Wednesday night with lows dropping
into the 40s to near 50F. Guidance has struggled with a another
shortwave rounding the base of the broad upper trough Wednesday
night into Thursday and whether it would move from southern New
England and brush the Downeast coast. Chances have trended lower
with the latest analysis and guidance, but have maintained
chance PoPs on the coast later Wednesday night into Thursday.
Further north, we have trended towards less cloud cover, but
seasonably cool highs in the low to mid 60s.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A long wave upper trough will slowly move out of the area in
favor of a high amplitude upper ridge during the period. While
the upper trough remains in place, there is a chance of showers
towards the coast Thursday night. A few light diurnally-driven
showers may develop on Friday too, but the overall trend will be
towards lower PoPs and warmer temperatures as the week draws to
a close. The upper ridge begins building Friday and will crest
over the area Sunday into Monday. High temperatures will move
from just below seasonable norms on Friday towards slightly
above normal by Sunday into Monday.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: Aroostook Terminals...VFR/MVFR conditions this
evening will decrease to MVFR, and then IFR later tonight in
low cigs and showers. LLWS is expected overnight. SE winds
10-15 kt with gusts 20 kt. By Tuesday, IFR/LIFR conditions
throughout the day. Scattered afternoon showers. Isolated
thunderstorm possible but too low confidence to include in
current TAF. S to SW winds 5 to15 kt.
Downeast Terminals...MVFR/IFR conditions this evening will
decrease to IFR/LIFR later tonight and remain IFR/LIFR with
rainshowers and patchy fog. LLWS is expected overnight. SE
winds 10 to 15 kt. For Tuesday, IFR/LIFR conditions in rain
showers. S to SW winds 5 to 15 kts.
SHORT TERM:
Tue night...Fog is possible southeast of HUL and BGR to include
locations such as Princeton, Machias and Eastport. Thunderstorms
will quickly end in the evening. Otherwise VFR. Light SW winds.
Wednesday...VFR. A chance of afternoon thunderstorms towards
Machias, Eastport, BHB and possibly BGR. NW winds 5 to 10 kt.
Wednesday night into Saturday...Prevailing VFR conditions. N to
NW winds 5 to 10 kt.
&&
.MARINE...
NEAR TERM: A Small Craft Advisory remains in affect overnight
through Tuesday for the outer waters, and through Tuesday
afternoon for the intra coastal zone. Visibility will be reduced
at times to 1 to 3 NM in showers and patchy fog into Tuesday.
SHORT TERM: Seas just over 5 ft may necessitate extension of the
SCA for outer waters Tuesday night. Otherwise, light winds are
expected. Southwest winds on Tuesday night into Wednesday will
shift to northerly for Wednesday night into late week. Fog is
likely Tuesday night and is expected to move away from the
waters with a cold front on Wednesday.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory until 8 PM EDT Tuesday for ANZ050-051.
Small Craft Advisory until 2 PM EDT Tuesday for ANZ052.
&&
$$
Near Term...TWD/LaFlash
Short Term...MCW
Long Term...MCW
Aviation...TWD/LaFlash/MCW
Marine...TWD/LaFlash/MCW
Area Forecast Discussion
National Weather Service Peachtree City GA
910 PM EDT Mon May 27 2024
...Evening Update...
.UPDATE...
Issued at 847 PM EDT Mon May 27 2024
Scattered convection is still ongoing primarily across west-
central and south-central GA this evening. Per the latest SPC
mesoanalysis, this convection appears to be elevated, given the
CIN currently in place. This is also reaffirmed by the latest 00z
FFC sounding. Nevertheless, a few strong and isolated severe
thunderstorms will still be possible capable of producing frequent
lightning, gusty winds, and small hail. A Severe Thunderstorm
Watch remains in effect for much of south- central GA until 10 PM.
With this latest forecast update several counties in east-central
GA have been removed from the watch. As the evening progresses,
additional counties are likely to be removed from the watch prior
to the expiration time. As we head into the overnight hours, our
concern shifts to hydro particularly along the southern CWA
boarder (portions of Stewart, Webster, southern Marion and Schley,
Sumter and Crisp counties). These areas can typically take a
decent amount of rainfall given the soil type but several rounds
of locally heavy rainfall have impacted these areas and any
additional rainfall may pose a localized flooding threat
overnight. At this time 2 to 3 inches look to have occurred. So
certainly something to monitor over the next few hours with
convection still present in that area.
Patchy fog will be possible in low-lying areas and/or areas that
received an appreciable amount of rainfall today. A surface front
will continue to push through the CWA overnight resulting in
drier conditions for Tuesday and perhaps through mid- week as high
pressure builds across portions of the southeast.
&&
.SHORT TERM...
(This afternoon through Tuesday)
Issued at 246 PM EDT Mon May 27 2024
The main line of thunderstorms has moved out of the area, leaving a
boundary stretching from Heard County over through Bibb County. A
couple storms continue to move along this boundary, occasionally
spinning up as they ingests vorticity and MUCAPE of around 2000
J/Kg. This storm is likely to remain at or near severe levels
through the next few hours.
A few storms are possible north of the boundary this afternoon as
the larger mid level trough and sfc cold front pushed through. These
storms will be isolated in nature although a storm becoming strong
cannot be ruled out. Storms along and south of the boundary will be
more scattered in nature. These southern storms also have a greater
potential to become strong to even severe given the atmosphere has
not quite been worked over just yet.
With current cloud coverage, temperatures continue to
most models. CAMs overall struggled with this system, however the
HRRR seems to be doing the best of all of them.
The good news is that once this system moves through, conditions
clear and dry out. Winds will be light but noticeable tomorrow and
highs will reach back into the mid-80s.
SM
&&
.LONG TERM...
(Wednesday morning through next Sunday)
Issued at 246 PM EDT Mon May 27 2024
With active weather ongoing across portions of the forecast area,
only minor adjustments have been made to the extended forecast based
on the latest guidance. The previous discussion follows...
.PREVIOUS DISCUSSION...
(Tuesday night through Sunday)
Issued at 328 AM EDT Mon May 27 2024
The extended forecast starts off dry as high
pressure slowly builds in from the northern plains and western
great lake states. With this ridge and drier airmass will come
slightly cooler temps for the middle to the end of the week. Temps
Wed through Fri will see highs mainly in the lower to middle 80s.
Moisture begins to creep back in for the weekend and could see
precip chances move back in for Sat/Sun.
01
&&
.AVIATION...
(00Z TAFS)
Issued at 740 PM EDT Mon May 27 2024
Sct convection continues for areas primarily south of I-20 this
evening and is expected to gradually dissipate closer to 03z.
Cigs/vsbys largely remain VFR, though MVFR cigs/vsbys will be
possible in association with any convection that occurs. MVFR
vsbys will be possible between 06-12z at CSG/MCN. Skies are
expected to clear out after 06z with SKC expected on Tuesday.
Winds will be light/VRB tonight switching to the NW 5 to 10kts
with gusts nearing 22kts Tuesday afternoon.
//ATL Confidence...00Z Update...
Medium confidence on TSRA potential at ATL through 02z.
High confidence on remaining elements.
07
&&
.PRELIMINARY POINT TEMPS/POPS...
Athens 66 86 61 85 / 20 0 0 0
Atlanta 68 86 65 84 / 20 0 0 0
Blairsville 59 77 54 76 / 10 0 0 0
Cartersville 64 84 59 83 / 10 0 0 0
Columbus 69 90 66 88 / 50 0 0 0
Gainesville 65 83 61 83 / 20 0 0 0
Macon 68 89 63 88 / 50 0 0 0
Rome 65 85 60 83 / 10 0 0 0
Peachtree City 66 86 62 85 / 30 0 0 0
Vidalia 72 90 67 89 / 60 10 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...SM
LONG TERM....01
AVIATION...07
Area Forecast Discussion
National Weather Service Grand Forks ND
1018 PM CDT Mon May 27 2024
.KEY MESSAGES...
- Another round of showers and thunderstorms arrives Thursday
into Thursday night, with a 50% chance for more than 0.50
inches over this 48 hour period
&&
.UPDATE...
Issued at 1018 PM CDT Mon May 27 2024
There is still just enough elevated instability/marginal mid
level lapse rates with the passing shortwave trough that
additional light showers (and a few lighting strikes) are
moving through the region, with a more definitive end to rain
behind the mid level trough axis. Instability should continue to
diminish through midnight and what forcing is there should move
to the southeast, but for now I adjusted PoPs/Wx to account for
a slower end to rain/thunder northwest to southeast.
UPDATE
Issued at 658 PM CDT Mon May 27 2024
RAP analysis already shows a decrease in low level lapse rates
and as the sun sets this should continue with MLCAPE rapidly
decreasing. Limited elevated instability/marginal mid level
lapse rates may still support a few lingering lighter showers
beyond sunset, but the bulk of activity should end by 03Z. The
had be a few marginal updrafts that supported smaller hail and a
few gusts in the last few hours but this threat has also started
to wan as shallower updrafts reflect decreasing instability
trends.
&&
.DISCUSSION...
Issued at 256 PM CDT Mon May 27 2024
Another interesting day with boundaries and shortwaves pushing
through the FA. The first shortwave pushed south and east of the
FA by early afternoon, and it is now affecting south central
Minnesota. There is also a scattered line of showers and storms
from Devils Lake to Garrison to Watford City. This area saw a
little more sun today, so it has squeaked out about 500J/kg of
MLCAPE, but weak effective shear. Finally a secondary shortwave
was located over southern Manitoba, which will move across the
FA tonight into Tuesday morning. After this last shortwave moves
through there should finally be a couple of dry days as 500mb
ridging moves back in. As this ridge pushes east, rain chances
return again for Thursday and Thursday night, and possibly
Friday night into Saturday morning.
The regional radar clearly shows the activity around each of the
areas mentioned above. This activity is fairly scattered (30-50%
coverage) and will likely hang around well into the evening.
Model guidance is indicating another batch of lower clouds
dropping from southern Manitoba into the northern FA around
sunrise Tuesday. This area continues to slide southward through
the morning, as it slowly thins. This, along with fairly steady
northwest winds in the 5 to 10 mph range should prevent much fog
from forming. There should be more sun around by Wednesday, but
temperatures may only struggle to get back to normal (around
70F).
As mentioned above, the next round of rainfall will move from
west to east across the FA Thursday into Friday morning. This
has been pretty well advertised in the ensemble solutions. The
more notable change today is that there may well be a break in
the precipitation after this initial line of precipitation moves
through. Therefore, eastern North Dakota could dry out again
Thursday evening, and areas east of the Red River could too on
Friday. However, so far anticipated precipitation amounts
shouldn`t deviate too much from the mention above (50% chance
for more than 0.50 inches over a 48 hour period). Behind this,
there could be another wave for Friday night into Saturday
morning.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 658 PM CDT Mon May 27 2024
Several areas of showers are moving across eastern ND and
northwest MN, with coverage already starting to decrease west to
east. There is still a low chance for a few light showers
overnight, but chances will be too low to linger mention beyond
03Z. Under some of these showers in the afternoon/early evening
ceilings have dropped to 3000 FT AGL, but this is transitioning
east with the main activity and VFR should prevail through 11Z
once the current activity ends. There is still a strong signal
for more widespread MVFR (localized IFR) stratus to arrive in
the 11-14Z period northwest to southeast Tuesday morning,
overspreading eastern ND and northwest MN as surface high
pressure builds into the region. Improvement back to VFR is
favored by midday as daytime heating/mixing increases.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...DJR
DISCUSSION...Godon
AVIATION...DJR
Area Forecast Discussion
National Weather Service Goodland KS
940 PM MDT Mon May 27 2024
.KEY MESSAGES...
- Relatively mild conditions with highs around 80 and winds
generally below 10-15 mph are forecast for Memorial Day and
Tuesday. A few non-severe, showers and storms are possible.
- Warm and active pattern is expected through the work week,
with chances for storms bringing an associated flooding risk.
&&
.UPDATE...
Issued at 830 PM MDT Mon May 27 2024
18z/00z NAM and latest HRRR model runs are all showing modest to
significant CAPE in the 1km and 2km layers moving into the
southern and southwest portions of the forecast area from the
south in the 12z-16z timeframe. CIN values at 1 and 2km are very
low. It appears that a 700mb disturbance will move into the area
of instability to support at least a slight chance of
thunderstorms in the counties listed above in the early to mid
morning hours. Should thunderstorms develop, they would be
capable of producing hail up to the size of ping pong balls.
From now through 12z, we should start seeing a slight increase
in shower/thunderstorm activity as weather systems move off the
Palmer Divide and Cheyenne Ridge and through the area. At this
time, severe weather is not expected with this activity.
&&
.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 150 PM MDT Mon May 27 2024
Abundant sunshine, light winds, and near normal temperatures
are making for a pleasant afternoon this Memorial Day. Overnight,
temperatures fall into the middle 40s to middle 50s. A weak
wave moving through later this evening into the morning hours
may initiate a few sprinkles/showers or at least an increase in
mid-level cloud cover.
A more active pattern returns following the holiday as we head into
the work week, bringing decent moisture into the region. This uptick
in moisture will allow for an increase in storm chances as waves
continue through the flow; additionally will be monitoring for
flooding potential as multiple days of locally heavy rainfall are
possible.
While the upper ridge moves over the Rockies on Tuesday,
an embedded disturbance will move through from the southwest,
introducing slight chance to chance PoPs by afternoon, continuing
into the evening and overnight period. A few storms may develop by
mid afternoon over eastern Colorado and move generally east-
southeastward across locations along/south of I-70. PWAT values are
forecast to be in the ~1-1.25 inch range. WPC continues a marginal
risk for excessive rainfall across far southern portions of the
area, including Greeley and Wichita counties. Severe weather is
currently not expected. Afternoon highs are forecast in the low to
mid 80s; overnight lows are forecast in the low to mid 50s.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 150 PM MDT Mon May 27 2024
Around mid-week, the upper ridge will move over the Plains, and an
upper trough will enter the western CONUS. This will shove the ridge
eastward and prompt shower/storm development by Wednesday afternoon-
evening. SPC continues a marginal risk for severe weather across
western portions of the area, generally along/west of Hwy 27.
Primary hazards with any severe storms include large hail and
damaging wind gusts. Guidance is picking up on storm development
over the high terrain to our west in the afternoon, tracking
eastward into our area and clustering together by the mid-afternoon
to evening hours. WPC also continues a marginal risk for excessive
rainfall across the entire area on Wednesday.
During the latter part of the work week, the upper low swings across
the western Canada/US border, generating additional waves as it does
so, allowing better chances for showers/storms (greatest chances on
Thursday at around 50-75% when PWAT values approach 1.5 inches
across eastern portions). Severe weather along with a flooding risk
will be possible. Shear values to around 30-35 knots and CAPE values
reaching 2000-3000+ J/kg are forecast for Thursday; lesser
instability (CAPE to around 1000-1500 J/kg) but greater shear (~50-
60 knots) forecast for Friday. WPC has included locations generally
east of Hwy 27 in at least a marginal risk for excessive rainfall on
Thursday; the slight risk clips eastern Graham county. Friday`s PWAT
values come down into the 0.8 to 1.15 inch range - some flooding may
still be possible, concern will focus on locations receiving heavy
rainfall in previous days, resulting in saturated soils.
Heading into the weekend and start of the next week, there is lesser
confidence at this range; however, the current forecast calls for
slight chance showers/storms and a warming trend.
Regarding temperatures, highs are forecast generally in the upper
70s to middle 80s, slightly cooler at the close of the work week.
Highs might then climb into the upper 80s to near 90 by the
start of the next week. Overnight lows are forecast generally in
the 50s.
&&
.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 940 PM MDT Mon May 27 2024
KGLD...VFR conditions are expected through the period. A light
east wind at taf issuance will continue through 21z before
increasing a bit with gusts up to 20kts from 22z-02z. After 03z,
winds will be from the southeast around 10kts. There are a few
windows of opportunity for showers/thunderstorms to impact the
terminal. The first is from taf issuance through about 09z as a
weather system moves through from the west. The second is after
18z with the best chance (only 30% or so) after about 03z. Given
the continued to low confidence and spotty nature of the
showers/thunderstorms will continue to not mention in the taf
forecast at this time.
KMCK...VFR conditions are expected through the period. A light
and variable wind is expected from taf issuance through 16z.
From 17z-02z, an east wind up to 11kts is expected. After 03z,
an east-southeast wind up to 10kts is expected. Presently,
showers and thunderstorms are not expected to impact the
terminal.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...None.
NE...None.
&&
$$
UPDATE...99
SHORT TERM...CC
LONG TERM...CC
AVIATION...99
Area Forecast Discussion
National Weather Service Gray ME
1010 PM EDT Mon May 27 2024
.SYNOPSIS...
A warm front will lift north, passing through the region
tonight. A cold front then passes overhead Tuesday. An upper
level trough slowly crosses the region Wednesday through Friday
with more scattered showers and near seasonable temperatures.
High pressure passes south of the area this weekend.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
1010 PM Update...No significant changes to the going forecast
with only minor tweaks to align with observed trends. Main band
of rain has overspread NH into western ME with area gauges
showing the heaviest rainfall rates of 0.5 to 0.75 inches per
hour. Total amounts thus far topping out around 1 inch across
the higher terrain of SW NH. The threat for convective processes
remains low and given the recent trends the threat for flooding
is low.
7 PM Update...Have mainly refined PoPs based on latest trends
in Hi Res guidance, which did not result in any significant
changes to the going forecast. Latest RAP analysis shows
instability remains south and west of the area with recent CAMs
showing some pockets of weak elevated instability crossing the
area with the main batch of rain. Have trimmed back thunder
coverage tonight because of these trends and there has also been
a slight downward trend in QPF. Nevertheless, with a plume of
high PWAT air sliding over the area will be watching for bouts
of moderate to heavy rain with recent runs of the HRRR
suggesting rainfall rates may approach 0.5 to 0.75 inches per
hour. Rain will end west to east tonight starting just after
midnight along the CT Valley and exiting eastern zones around 6
am.
Previously...
A large area of low pressure will continue to track through
southern Canada tonight. This will allow a cold front to push
east and into New England. Ahead of this front, plenty of
moisture will be streaming poleward with PWs increasing to
nearly 2 inches along a north to south axis tonight. Showers
will increase in coverage overnight along with fog being
persistent. The latest HREF has high probabilities for
visibilities to remain below a mile especially along and near
the coastline. Patchy drizzle will continue as well. However,
with the pops already running high, will not include in this
upcoming forecast package.
QPF...Locally heavy rain will fall across the region, especially
along the upslope regions of the northern mountains and
foothills.
It will be a muggy night with dew points running high, mainly in
the 55 to 65 degree range. Overnight lows will drop into the mid
50s to mid 60s as well.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
Drier air will attempt to enter the region on Tuesday behind a
departing short wave. Sunshine will allow temperature to climb
into the 70s. It will be a little cooler right along the
shoreline due to a sea breeze.
The warmth will allow for a few showers and thunderstorms to
form during the day. These will mostly be confined to the
northern mountains. Some patchy fog may develop once again
Tuesday night. The overnight lows will be relatively uniform
across the region, mostly in the 50s by morning.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Overview: A mid-level trough and cutoff low pressure system
will remain near Northern New England through Friday, which will
result in continued chances for scattered showers at times
along with near average temperatures. Drier conditions are then
likely by next weekend.
Impacts: Little to no major weather related impacts are expected.
Forecast Details: A secondary surface cold front will cross from
north to south on Wednesday, which will allow for a continued chance
for scattered showers at times. Skies will be partly sunny south of
the mountains and mostly cloudy across the mountains and far north.
Temperatures will range from around 60 to the middle 70s from north
to south. Some weak daytime instability may allow for an isolated
thunderstorm but severe storms are not currently anticipated.
Scattered showers will remain possible through Wednesday night with
cool overnight temperatures into the lower to middle 40s. The cold
front will move over the Gulf of Maine on Thursday but a weak sfc
low may develop along it. This will result in scattered showers
through much of the day, especially south of the mountains. High
temperatures will remain cool with lower 60s across the north and
upper 60s to near 70 degrees south.
Showers will likely become more isolated in nature by Thursday night
as the front and weak wave of low pressure slides north and east of
the area. Low temperatures will be mostly into the 40s. High
pressure will build to our west on Friday but latest guidance
indicates an inverted trough may develop, which would result in cool
and showery conditions once again. This portion of the forecast is
of lower confidence though as heights will be rising through the
day. Therefore, capped PoPs to slight chance at this time. High
temperatures will be into the 60s to lower 70s. Drier and
slightly warmer conditions are then likely next weekend as an h5
ridge axis moves overhead and sfc high pressure slides
eastward.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Short Term...Areas of IFR and LIFR conditions especially along
and near the coast where the fog will be most prevalent.
Otherwise, showers and a few thunderstorms will become more
numerous as the night goes on. On Tuesday, there will be a
chance for a shower or thunderstorm with IFR conditions mainly
confined to the north. Partial clearing expected Tuesday night
with mainly VFR conditions. However, there may be some patchy
fog developing during the night.
Long Term...Mainly VFR conditions are expected outside of any
scattered -SHRA and potential nighttime FG. Winds will be
primarily out of the west at or below 20 kts.
&&
.MARINE...
Short Term...SCA conditions will continue tonight as a southeast
gradient continues. Seas will be in the 4 to 6 foot range along
the outer waters. Southeast winds will veer to the south on
Tuesday with SCA conditions remaining. Periods of fog and low
stratus expected tonight into Tuesday morning, which could
cause low visibility. This improves during the day Tuesday as a
cold front passes over the waters.
Long Term...Seas up to around 5 ft are possible across the outer
waters Wednesday through part of Thursday but otherwise westerly
winds and seas will likely remain below thresholds hazardous to
small crafts.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 4 PM EDT Tuesday for ANZ150>152-154.
&&
$$
NEAR TERM...Cannon/Schroeter
SHORT TERM...Cannon
LONG TERM...Tubbs
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
Issued by National Weather Service Wilmington OH
821 PM EDT Mon May 27 2024
.KEY MESSAGES...
- Cooler, drier air will eventually filter into eastern Kentucky
behind an exiting cold frontal system. Generally cooler and less
humid weather will then be in place over the next several days.
- Warmer and somewhat more humid weather will return by next
weekend, with our next area-wide chance of showers and
thunderstorms.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 525 PM EDT MON MAY 27 2024
Looking forward to quiet, pleasant weather for this cycle of the
short term. Upper level low over the Great Lakes Region will keep
a mean trough in place aloft across the eastern CONUS. Weak short
wave disturbances will rotate around the southern periphery of the
mean trough, but there appears to be no significant impacts to
speak of over our forecast area through the short term. Drier,
cooler air will gradually filter into eastern Kentucky later
tonight and tomorrow behind an H850 trough, which is passing
through the region, currently entering our western most zones, or
just entering eastern Kentucky.
Sensible weather features seasonably cool afternoons and chilly
nights, especially in our sheltered, typically colder valley
locations. Northwest flow will tend to provide increasingly
clearer sky conditions with a west-northwest gradient wind.
Temperatures will drop into the mid 50s tonight and low to mid 50s
tomorrow night. While guidance keeps our temperature in the 50s,
it is possible some of our coldest valleys could slip into the
upper 40s tomorrow night. Afternoon highs will generally be in the
low to mid 70s tomorrow. No hazards to deal with during the short
term. However, the most recent runs of the hrrr do suggest a new
trend in the forecast for this evening in that there may be some
isolated shower development along the H850 trough this evening as
it passes west to east across the area. Will monitor for possible
updates to our PoPs as necessary.
.LONG TERM...(Wednesday through Monday)
Issued at 650 PM EDT MON MAY 27 2024
The 27/12Z model suite analysis beginning Wednesday morning shows
an upper level longwave trough over Eastern Canada down across
the Great Lakes and Ohio Valley. An upper level ridge extends from
the Southern Plains northward into Manitoba ahead of another
trough moving ashore the Pacific Northwest. At the surface, low
pressure is found over eastern Quebec with a cold front trailing
back to the southwest around the southern shores of the Great
Lakes. Strong Canadian high pressure is centered over northwest
Ontario behind the front.
The cold front will brush northeast Kentucky on Wednesday
afternoon as it attends the passage of the upper level trough axis
and a lead shortwave. This will bring slight chance/low chance
POPs to locations northeast of KY Route 15. Surface high pressure
then sinks to the Great Lakes on Thursday while additional
shortwave energy continues to rotate through and reinforce the
troughing aloft. This will keep relatively cool, dry northerly
flow in place, holding 850mb temperatures mostly in the 5-10 C
range. The surface high will then shift east Friday along with the
upper level ridge axis while subsiding and weakening. Once the
surface high is off to our east, southerly return flow will bring
increasing moisture levels and warmer temperatures for the first
three days of June. Passing disturbances will interact with this
moisture to bring daily slight chance/chance POPs from Saturday
onward.
In terms of sensible weather, look for sporadic showers to bubble
up on Wednesday northeast of KY Route 15, with the highest
chances ~30% over the Big Sandy Basin. Temperatures will be
seasonably cool with highs in the lower and mid 70s. From
Wednesday night into Friday night, low humidity, cool
temperatures, and fair weather will prevail with northerly
breezes. Look for daily highs in the lower to mid 70s while night
time lows range from the mid 40s to mid 50s. Daily shower and
thunder chances then return over the weekend and early next week
as southerly flow brings rising moisture levels and temperatures
moderating into the lower to mid 80s by Monday, with lows in the
upper 50s to lower 60s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 720 PM EDT MON MAY 27 2024
Mainly VFR conditions are forecast through the period. The only
exceptions should be sub-VFR conditions in some very isolated
showers this evening, and in localized valley fog in south central
and southeast Kentucky overnight and early Tuesday morning. The
fog is not likely to affect TAF sites. Winds will diminish to
around 5 kts or less tonight, and pick up from the west around 10
kts during the day on Tuesday.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HAL
LONG TERM...
AVIATION...RAY
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1033 PM CDT Mon May 27 2024
.KEY MESSAGES...
- Scattered showers and thunderstorms will be possible mainly
along and north of I-70 through early this evening and again on
Tuesday afternoon.
- Wednesday and Thursday is expected to be dry before an unsettled
weather pattern brings a chance of showers and thunderstorms
beginning Thursday night through the weekend. Temperatures will
be close to normal.
&&
.SHORT TERM... (Through Late Tuesday Night)
Issued at 238 PM CDT Mon May 27 2024
Scattered showers and thunderstorms have developed across north
central Missouri this afternoon and are moving to the east. Expect
them to continue to move to the east along and north of I-70 as the
latest RAP is showing MLCAPES of around 1000 J/kg ahead of a subtle
shortwave trough. Convection will likely diminish after after 00Z
with loss of daytime heating and as the shortwave moves off to the
east of the CWA. We will see a second round tomorrow afternoon
across the northern CWA as NAM/GFS is showing another shortwave
moving across the Upper Midwest. This weak ascent combined with
forecast SBCAPES of 500-1000 J/kg suggests the potential for a
slight chance of showers and thunderstorms.
Temperatures will be at or just be normal for late May through
Tuesday night as we will be in neutral or weak cold air advection.
Britt
&&
.LONG TERM... (Wednesday through Next Monday)
Issued at 238 PM CDT Mon May 27 2024
Generally dry weather is expected mid-late week before the weather
becomes more active as we enter next weekend. There is general
agreement between the global models and LREF that a upper trough
over Great Lakes will move east and off the East Coast at the same
time that a Great Plains ridge will move into the Midwest by Friday.
This will set up northwesterly flow aloft Wednesday into Thursday at
the same time a surface high moves across Missouri and Illinois. The
pattern will begin to change next weekend once the upper ridge moves
past the area and the pattern become quasi-zonal over the Midwest.
There is good agreement between the global models with timing and
strength of the lead shortwave on Friday night, but less so with
subsequent troughs that will move through the area into early next
week. The LREF is showing that about 50 percent of it members
having rain on Friday night with at least some chance (20-30
percent) through the rest of next weekend.
Temperatures will be at are a bit below normal into Friday as winds
will have a north to east component which favor cooler weather
before turning out of the south over the weekend. At the same time,
850mb temperatures will climb from around 10C to 15C. I have higher
confidence mid-late week as the NBM IQR is 5 degrees or less
Wednesday through Friday before becoming larger under the zonal flow
over the weekend.
Britt
&&
.AVIATION... (For the 06z TAFs through 06z Tuesday Night)
Issued at 1031 PM CDT Mon May 27 2024
Dry, VFR conditions will prevail at the terminals through the
valid TAF period. Aside from a low threat for thunderstorms across
west-central Illinois that may impact KUIN, precipitation is not
forecast. Winds will remain generally northerly through Tuesday
night, with increasing gusts during the day Tuesday. The gusts
will diminish after sunset when diurnal heating ends.
MRB
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
842 PM CDT Mon May 27 2024
.KEY MESSAGES...
- Scattered showers and thunderstorms are producing small hail
and frequent lightning this afternoon across central and
southern MN. Brief funnel clouds have been reported at times
as well.
- Things become fairly quiet with seasonable temperatures and
the next chance for widespread rain arriving near the end of
the week.
&&
.UPDATE...
Issued at 831 PM CDT Mon May 27 2024
With today`s shortwave exiting southeast MN, the loss of daytime
heating, and the fact that we`ve already consumed a good deal of
our instability earlier in the day, shower intensity and
coverage has been rapidly diminishing in the last hour as
expected. We don`t have to wait long for the next shortwave,
which is already pushing into northern NoDak. This wave will be
working through our MN portion of the forecast area late tonight
through Tuesday morning. Given what just happened earlier in the
day, there will be less moisture and instability to work with
for this wave, but we should still see scattered showers work
across the area through the morning as this initial part of the
next shortwave works through. For Tuesday afternoon, we`ll have
cyclonic flow aloft, with one more piece of shortwave energy
heading into western WI, which will support another round of
scattered showers and storms. Highest confidence in afternoon
showers occurring is for east of I-35, but several of the CAMs
show showers extending back across much of central MN, so have
expanded 20% pops back west a ways for Tuesday afternoon. After
this wave on Tuesday, we get a break from precip Wednesday and
Thursday.
&&
.DISCUSSION...
Issued at 229 PM CDT Mon May 27 2024
A broken line of thunderstorms has tracked through portions of south-
central Minnesota already this afternoon, resulting in multiple
reports of half-inch or smaller hail. A broader area of scattered
showers/storms encompasses much of central and southern Minnesota
behind the aforementioned line. Hail and lightning with these cells
are much more sporadic and limited compared to the broken line. This
whole smattering of storms will continue to move southeastward this
afternoon in tandem with the exiting surface low pressure system.
Brief funnel clouds, and a weak landspout or two, are possible with
these storms, especially along the boundary associated with the
occluded low. SPC`s mesoscale analysis page highlights increasing
values of the non-supercell tornado parameter, pushing above 6 for
areas near the MN/SoDak/NoDak border. Any severe potential should
diminish early this evening, and scattered showers/storms will
gradually taper off into tonight.
A secondary, and more disorganized shortwave will eject down over
the Great Lakes region tomorrow, bringing a chance (30-50%) of rain
for areas along and east of I-35. Storm total QPF will be light and
while a rumble or two of thunder is not out of the question,
anything severe is unlikely.
Surface high pressure will move in Wednesday morning, resulting in a
a couple of nice days with mostly sunny skies and light winds.
Temperatures are expected to generally trend upwards for the near
future, with persistent highs in the 80s possible by the start of
next week. Lows will also be trending up after Tuesday night, with
low 60s possible heading into early next week.
Nearing the end of this week, a broad upper-level trough
pattern will slide eastward from the Pacific NW bringing off-
and-on chances for showers/storms through the weekend. Any
severe threat looks to stay further west, or is too low for
predictability at this time. Long-term models generally show a
large positive 500hPa height anomaly building over the western
half of the CONUS by early next week, supporting the idea of a
general upward trend in temps and a potentially less active
period of weather ahead.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 622 PM CDT Mon May 27 2024
Shortwave number 1 is now moving into southeast MN, with the
next on deck already dropping out of Canada and into northern
NoDak. As the first wave continues to sag southeast, we`ll see
occasional pop-up showers through 3z, but we`ve pretty much
consumed the available instability for any storms, so a rapid
demise in the showers is expected as the move into places that
have already seen rain. Wave number 2 won`t have as much
moisture to work with, but will have the potential for some
scattered showers tonight through Tue afternoon, with the
greatest likelihood of precip residing at RNH/EAU. The HRRR
provides a reasonable expectation for what this second
shortwave will be able to do. For cigs, did remove any MVFR
mention this period. Occasional MVFR cigs will be possible with
any showers, but on the whole, VFR clouds will dominate.
KMSP...Still a few showers to contend with, but seeing how the
last round of rain knocked temps back into the 50s, activity
back over Wright county will struggle to make it all the way
over to MSP. Next round of showers will be more of the hit-or-
miss variety. There will be an initial chance for shra 12z-17z
as the shortwave is moving in, with afternoon pop up showers not
out of the question as well.
/OUTLOOK FOR KMSP/
WED...VFR. Wind NE 5-10 kts becoming SE.
THU...VFR. Wind SE 10-15 kts.
FRI...Mainly VFR. Chance -SHRA/MVFR. Wind S 10-15 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
UPDATE...MPG
DISCUSSION...BED
AVIATION...MPG
Area Forecast Discussion
National Weather Service Marquette MI
717 PM EDT Mon May 27 2024
.KEY MESSAGES...
- Rain continues in the far eastern UP this evening, then additional
rain showers move across the UP later tonight through Tuesday.
- Below normal temperatures for the first half of the week, with dry
weather returning midweek.
-Areas of frost expected Thursday morning.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 425 PM EDT Mon May 27 2024
Water vapor imagery and RAP analyses reveals two well-defined
shortwaves over the Great Lakes, one moving from the Lower Peninsula
into eastern Ontario with an associated deep surface low heading
towards the Quebec border. Another wave is dropping southeast
through central MN. As this second wave continues to move southward,
it will amplify the broad troughing over the region ahead of yet
another weaker wave that is already moving into Manitoba. Rain
showers continue to pivot into the eastern UP this afternoon as the
first low over eastern Ontario continues its eastward trek, with
plenty of lower-level cloud cover apparent on satellite. However, we
have pretty much dried up west of Hwy 41, and skies have even been
able to clear across the far western UP. This has allowed for some
convection to develop, apparent in agitated cu and weak radar
returns popping across Gogebic and Iron county. There is quite a
range in temperatures from west to east as areas that have cleared
out are climbing well into the 60s and even lower 70s, while most of
the eastern UP is struggling even to reach the mid 50s.
As rain across the eastern UP finally moves out of the area, a brief
window of dry weather is expected overnight. Cloud cover should fill
in across the west with the shortwave currently over MN moving into
central WI, and though precipitation associated with this should
largely stay out of the area, will not rule out some showers
reaching the far western UP later tonight.
Otherwise, expect temperatures to fall back into the mid/upper 40s
overnight. Winds remain elevated particularly across the eastern UP
on the back edge of the exiting system, which should help to limit
the development of fog in spite of plenty of lower level moisture.
&&
.LONG TERM /TUESDAY THROUGH MONDAY/...
Issued at 425 PM EDT Mon May 27 2024
Recent deterministic and ensemble guidance packages are continuing
to handle the up coming pattern consistently for Upper Michigan. The
long term pattern for Upper Michigan will start off with broad mid-
level troughing overhead as today`s surface low pulls away through
Ontario into Quebec. Within this flow, a shortwave will press east
through MN/WI into this evening followed by a weakening closed low
pressing through the Upper Great Lakes Tuesday. Afterwards, ridging
builds into the region for the latter half of the week followed by a
cold front for the weekend.
After a brief, mainly dry period overnight, the next shortwave
(currently over Manitoba) begins to drop through, ushering in a
cooler airmass as well as our next batch of rain showers. While the
better synoptic forcing appears to be south and west, increasing
instability through the day, coupled with the possible morning
shortwave, could support increasing coverage of showers through the
day in the west, and possibly a thunderstorm as well. Meanwhile,
look for temperatures to range in the 50s and 60s, coolest along
Superior amid onshore flow. Winds may turn breezy during the
afternoon, gusting up to around 20mph especially across the eastern
half of the UP.
Ridging and an increasingly dry airmass will build into the region
late Tuesday night and then persist through at least Friday. This,
alongside the cooler airmass will keep daytime highs of 50s and 60s
into Wednesday. Frost may be a concern for portions of the interior
west Tuesday night and will be for most interior locations Wednesday
night. Confidence is high (>75%) for patchy to areas of frost
Wednesday night. While our internal model certainty tool and NBM
probabilities suggest a 50% chance of falling below 35F for interior
portions of Upper Michigan, both EC and GEFS ensemble suggest PWATS
of 20-30% of normal. Given this, subsidence overhead, and the weak
winds, a freeze is also a possibility. Will note NBM guidance shows
around a 20% chance for lows below freezing. At this point, a Frost
Advisory seems likely (>75% chance) Wednesday night but will
continue to monitor model trends. While frost is also possible
Tuesday night, the timing of the drier air and potential for
continued winds above 5 mph suggest radiating out may be more
difficult.
Guidance also continues to suggest the dry and well-mixed boundary
layer will support plummeting dewpoints and RH falling below 30%
away from the lakeshores Wednesday and Thursday. A mitigating factor
for the fire weather risk, in addition to fairly light winds, will
be the widespread rain in the preceding days. Ridge axis builds into
the region Thursday night while another trough presses out of the
Rockies. Guidance consensus continues to suggest the surface high
and dry conditions will win out through at least Friday night, with
rain chances returning Saturday as a cold front moves through. June
may start off wet with a troughy-looking pattern setting up over the
Great Lakes.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 717 PM EDT Mon May 27 2024
VFR is likely to prevail thru this fcst period at IWD/CMX/SAW. A
disturbance dropping into the Upper Mississippi Valley may bring a
few -shra into western Upper MI late tonight and early Tue morning.
Only a VCSH mention was included at IWD. Do not expect conditions to
drop out of VFR even if a -shra occurs.
&&
.MARINE...
Issued at 425 PM EDT Mon May 27 2024
Behind an exiting surface low, winds continue to back to the NW over
eastern lake Superior and over to the west across the western half
of the lake. 20-25 kt gusts continue across the eastern half of the
lake through the evening hours, but should fall back to around 20
knots later tonight while winds remain below 20 knots to the west.
Wave heights of 4 to 7 feet should be expected across the east half.
The low will pull away tonight, but NW winds continue to gust to
around 20 kts through Tuesday before falling back Tuesday night.
High pressure builds across the lake on Wednesday supporting light
and variable winds and decreasing waves until Thursday midday, when
light easterly to southeasterly flow at 5-15 kt re-establishes
itself across the western lake, along with waves 1-3 ft. Winds then
veer to the south for Friday and into the weekend, but continue to
come in at around 5-15kts with waves around 1-3ft across the lake.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Beach Hazards Statement until 10 PM EDT this evening for
MIZ005-006.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...LC
LONG TERM...LC
AVIATION...Rolfson
MARINE...LC
Area Forecast Discussion
National Weather Service Las Vegas NV
751 PM PDT Mon May 27 2024
.SYNOPSIS...A stray thundershower or two is possible into early
this evening in the southern Sierra but otherwise dry conditions are
expected areawide. Afternoon breezes can be expected each day with
temperatures several degrees above normal into early next week.
&&
.UPDATE...Warm but quiet this evening as an upper-level ridge holds
over the Western US. The only notable weather-related topic is the
development of the Bird Springs fire just SW of Vegas. Last update
was 150 acres with containment at 15 percent. Fire-fighting
conditions become less favorable tomorrow with southwest breezes
increasing as a system moves into the PacNW. Winds are forecast to
be 10-15 mph in the afternoon with gusts up to 25 mph and RH values
around 10 percent. A weak ridging/zonal pattern looks to set up mid-
to-late week, keeping temps above normal and light afternoon
breezes. Largely dry conditions prevail through the forecast period,
with only low (10%) rain chances in the Sierra and our far northern
zones.
&&
.DISCUSSION...Extensive cumulus field across the central and
east central Nevada mountains just after noon. Satellite also shows
cumulus congestus becoming more apparent on the southern Sierra.
Latest run of the HRRR continues to shows several showers, maybe a
stray thunderstorm developing after 2 pm along the Sierra crest,
from upper Bishop Creek north into Mono County. Elsewhere,
seasonably warm temperatures will lead into a pleasant evening for
those final Memorial Day outings.
Hate to sound like a broken record, but model agreement remains good
in the synoptic scale features over the next week. Only real player
will be the passage of a trough through the northern tier states
Tuesday-Thursday. No significant winds expected from the system,
just our typical daily south-southwest breezes. Only minor day-to-
day temperature fluctuations with high generally 4-7 degrees above
normal. Last item, there is a wildfire in the lower CRV north of
Yuma that could send smoke/haze northward into the Parker
Strip/southern Mohave County at times.
&&
.AVIATION...For Harry Reid...Light east winds are expected through
the early afternoon. After 21Z, there is moderate confidence (60%
probability) that winds will become southeast. If this does not
occur, east winds will continue through the afternoon. No matter
what direction sets up for this afternoon, winds will remain under
light with a nearly 100% probability for wind speeds to remain under
10KT.
Typical overnight south-southwest winds set up this evening and will
continue through early Tuesday morning. After a brief period of
light and variable winds Tuesday morning, southeast winds at 8KT or
less are expected to set up around 18Z. Sometime in the afternoon,
winds will shift southwest and increase. This likely wont occur
until at least 21Z, but could be as late as 23Z-00Z. Wind speeds
over 10KT are likely (80% probability or higher), with a low chance
(30%) for gusts over 20KT, when the southwest winds arrive. No
significant clouds or weather are expected through the period with
just a few cumulus clouds developing around 12kft this afternoon.
For the rest of southern Nevada, southwestern California, and
northwestern Arizona...Breezy south to southeast winds are expected
at KBIH this afternoon. Winds will remain elevated out of the
southeast after sunset before transitioning to a typical light
northwest wind around midnight. Gusts to around 20KT are possible at
KBIH this afternoon. At KDAG, typical breezy west winds will develop
around 00Z, with gusts falling off around midnight but continued
elevated wind speeds through the night. Otherwise, light and diurnal
wind patterns are expected across the region today through tonight.
No operationally significant cloud cover expected through the TAF
period.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
UPDATE...Woods
DISCUSSION...Pierce
AVIATION...Nickerson
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