Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/24/22
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1148 PM EDT Wed Mar 23 2022
.AVIATION...
Showers will persist over KMBS into the overnight, but end
elsewhere a mid level dry slot holds over the area. Occluded frontal
boundary will shift north and bring a transition from easterly to
southwesterly flow will some gusts to 20 knots or more. MVFR ceilings
should be the rule into Thursday with KMBS being the exception with
IFR/LIFR at least overnight into the morning Thursday.
For DTW...Easterly flow will veer to southwest around 06z with the
passage of a surface front. Ceilings should remain aob 5kft for a
majority of the forecast period (although periods of higher cigs
may occur at times).
.DTW THRESHOLD PROBABILITIES...
* High for ceiling at or below 5000 ft overnight into Thursday.
&&
.PREV DISCUSSION...
Issued at 336 PM EDT Wed Mar 23 2022
DISCUSSION...
Redevelopment of widely scattered to numerous showers is now
underway across northern Ohio given increasing upper-level
divergence from left exit jet support along with support from a
potent upper-level wave that will move across the Ohio Valley and
will clip southern Michigan. This activity will continue to fill in
across SE MI through the remainder of the afternoon and evening as a
surface low and occluded front gradually starts to pull north across
Michigan leading into the evening hours. Embedded elevated thunderstorms
will be possible with all activity given the established stronger
mid- level lapse rates between 6.5 to 7.5 C/km and weak to modest
MUCAPE values ranging between 100 - 500 J/kg. The main severe weather
threat with stronger convection will be hail to or just above an
inch, generally confined to or south of I96 where the better
instability resides. The cooler easterly flow continues to hold the
warm sector south of the state line, which is very apparent with
temperatures in the upper 40s across southern Monroe county, but
nearing 70 degrees at Toledo -- A 20 degree spread over 10 miles. The
RAP mesoscale analysis does suggest some surface based instability
poking into portions of southwestern Monroe into Lenawee county into
the evening hours. This could bring the possibility to see an
isolated damaging wind gusts with any stronger convective
development. An isolated tornado cannot also totally be ruled out
along or south of this boundary given the more favorable low level
helicity and low level lapse rates, but again this is highly
dependent on the intrusion of the warm sector -- Contrary to the RAP
cycles, the latest HRRR holds all surface instability south of the
state line, with instability waning as the front finally pushes north
into Michigan.
Better coverage of rain showers and thunderstorms will decrease from
01Z - 05Z from south to north as the boundary settles across central
Michigan and better jet support exits east. As the occluded system
gradually travels northeast through the day on Thursday, the better
rain chances will develop along this boundary where the better theta-
e gradient resides, favoring precipitation chances along the Tri-
Cities into the northern Thumb through Thursday morning. Drizzle or
light rain showers will be possible for locations south of this
boundary through the morning hours, with decreasing odds for PoPs
towards the state line. Rain chances and coverage will then again
increase from north to south through Thursday afternoon and evening
as trough axis starts to shift east along with return flow from the
departing low drawing a weak cold front across the state. H850
temperature will drop below freezing with enhanced caa after 18Z on
Thursday, and will support a possible rain/snow mix or changeover to
melting snowflakes across the Tri-Cities into northern Thumb for
lingering precipitation leading into Friday morning. No snow
accumulation is expected.
A disorganized thermal trough will hold over the Midwest and Great
Lakes and will be reinforced as a strong wave travels south across
the Plains into the Midwest through Friday. There will be a lack of
jet or frontal support on Friday and into the first half of the
weekend as a series of mid-level waves either glances the southern
Great Lakes or quickly moves over the area. Any precipitation
observed on Saturday will likely fall as snow given the ongoing caa
with h850 temperatures to -4C and overnight lows rebounding from
near freezing. Below normal temperatures will accompany this
enhanced thermal trough this weekend, leading into early next week.
Highs in the lower 40s on Saturday drop down into 20s early Sunday
morning, with the coldest temperatures expected Sunday as highs may
struggle to break the freezing mark. A Canadian high pressure system
with very dry air will Sunday into Tuesday, bringing little chances
for precipitation. Will need to monitor any chances for lake effect
snow across Lake Huron early next week as the latest ECMWF run drops
h850 temperatures down to -20C by Monday morning.
MARINE...
A weakening low pressure system will gradually lift across the
region tonight. A slow decline in both wind speed and gust magnitude
of prevailing easterly flow will occur through this time. Strongest
winds going forward into the evening hours will exist across
northern portions of lake Huron, where gusts to gales remain
possible. Elsewhere, conditions ease sufficiently to allow for
expiration of ongoing warning headlines. A low potential for
thunderstorms exists through the evening, mainly across lake St
Clair and Lake Erie. Modest winds from a southwest direction will
emerge in the wake of this system for Thursday. Winds shift to
westerly and remain generally light through Thursday night as a cold
front tracks across the area. Westerly winds prevail through the end
of the week.
HYDROLOGY...
Widely scattered to numerous rain showers with embedded
thunderstorms will push from south to north across SE MI through the
evening hours. Any development of stronger storms will be capable of
producing a quick half inch to an inch of accumulation. Repeated
rounds of shower and thunderstorms will be capable of producing
localized higher amounts of accumulation totaling 1.5 to 2 inches.
The better probability of these higher localized totals will reside
south of I-69, where the better instability and thus stronger
thunderstorm chances reside. The better precipitation coverage will
diminish from south to north late tonight into Thursday morning.
Additional drizzle to light rain chances to then hold on across the
Tri-Cities to northern Thumb overnight, before increasing again
across the rest of Southeast Michigan later in the day on Thursday.
Additional rainfall totals of a tenth of an inch, up to around a
quarter of an inch, will be possible centered Thursday morning into
Friday morning. Given the prior precipitation, some rises to area
rivers and streams are expected. Ponding of water on roadways and
low-lying areas are also expected with thunderstorm activity.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...Small Craft Advisory until 4 AM EDT Thursday for LHZ421-441>443.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
&&
$$
AVIATION.....99
DISCUSSION...AM
MARINE.......MR
HYDROLOGY....AM
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Gray ME
1109 PM EDT Wed Mar 23 2022
.SYNOPSIS...
A slow moving storm complex over the Ohio Valley will drift
eastward and affect the region for the next couple of days.
Expect precipitation to start as snow and sleet before
transitioning to rain at lower elevations, but remaining a
wintry mixture across the north and mountains. Unsettled weather
will continue over the weekend with a mix of rain and snow
showers possible. Notably cooler weather expected into early
next week.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
11pm Update...Continued some tweaks to temps and sky cover. As
expected, warmer temps in the 40s continue across SW NH where
clouds have been prevalent since before sunset. Anywhere to the
north and east has cooled rapidly into the mid to lower 30s.
With dewpoints in the lower 20s and even upper teens, temps
should continue to lower across the Midcoast and ME capitol
region. It has been difficult finding model guidance to support
this temp gradient, but some HREF guidance blended in across the
cooler locations has been helpful. Temp falls should balance out
over the next few hours as thicker mid clouds advance NE. With
these cool temps in place, have brought the mention of some
light snow along the coast during precip onset before temps warm
into the day Thursday.
650pm Update...Just a few changes to sky con and temps at this
hour. Much of the area is still quite warm after a mostly sunny
day. Some of the temperature tweaks were with this fact in mind.
Brought in latest obs, and made sure of a faster cooling rate to
the north and east where much of the area is cloud free or
passing cirrus. To the SW, HRRR does a good job at keeping these
areas a bit warmer longer as clouds help insulate against
radiation loss into the early evening hours.
Previous Discussion...
Hybrid Miller-B system moving in from the W tonight with
weakeningwave in SW 500 MB flow tracking into New England from
the SE. initially will see decent WAA despite the dynamics
weakening as they system tracks toward ups. So look fro precip
to begin tonight, moving in from SW to NE mainly after midnight,
although around them in SW NH. Tricky call on initial p-types
in the S late tonight, with temps aloft borderline, as will be
boundary lyr temps in some areas inland, especially those areas
from around the NH lakes region into the ME lakes region. For
this reason, issued an advisory here late tonight into Thu
morning, because some areas are likely to see a short period of
FZRA, probably around the morning commute with temps 30-32.
Otherwise forecast thinking not very different from previous
forecast, with a brief bout SN/PL expected at the start in many
areas in the south, but with temps above freezing, these quickly
change to rain. Interior sections will hang onto SN/PL into Thu
morning.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
The weakening first wave will limit sfc flow a bit thu morning,
until the second wave develops further to our SW, and this will
allow E-SE flow to pick up, and should scour out any of the near
freezing near the sfc E of the mtns, which will change everything
to rain. In the foothills, shallower cold layer will be pushed
above marine lyr, but will hold below warm layer aloft, so
looking at elevations in the 1-3K foot range to stay as FZRA or
PL longest in these areas, and it is here where perhaps
0.25-0.3" of ice may be possible, especially in the Sunapees
and the lower elevation portions of the Whites. further N and E,
toward Rangeley and Jackman, should hold onto snow for much of
the day Thu, which will eventually mix with sleet or rain /or
perhaps a little FZRA as well. Here`s advisories are issued for
3-5" of snow. Precip will lighten up and begin intermittent or
drizzly in the afternoon before another round of steadier precip
moves in thu evening. Highs range from the low 30s in the mtns,
with the exception of SE downslope areas in the Whites which
could reach near 40. in the foothills and coastal plain, look
for highs of 35-40.
The second round of precip that moves through Thu evening will
be quicker to get in and out, and will be mainly rain in all but
the far NE zones, which will likely stay as a mix of SN/PL.
Could see a few sheltered areas stay FZRA as well, otherwise
all precip winds down during the pre-dawn, and could see it end
as a brief period of snow with no accums to speak of. Lows will
be in the upper 20s N to the mid 30s S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Warm/occluded front will be
lifting into the area Friday morning as a secondary surface low
develops over New England. The track/timing of the surface low will
greatly influence the extent of the warm air advection, which right
now looks to push to the foothills before the winds turn and colder
air returns, resulting in a large temperature range across the area
with highs near 60 in S NH and mid 30s in the mountains. Will
continue to see precipitation with a mix in the higher terrain
through the day, though some dry slotting is possible on the
backside of the low with lessening Pops during the day.
The larger pattern continues to show an upper level low/trough that
will pivot over the region for most of the long- term (-NAO phase).
This will favor unsettled conditions through the weekend with all
rain in southern areas during the day, however the thermal profiles
favor a transition/mix of snow both Saturday and Sunday nights for
most areas. The higher terrain will have the better chances to see
snow with light accumulations possible. The source region is limited
in moisture so precipitation amounts are expected to be light
despite the long drawn-out nature of the event.
Cold air advection kicks in behind a strong cold front on Monday,
favoring strong mixing and breezy conditions. The colder airmass
will linger into Tuesday with below normal temperatures. The
longwave trough is projected the deamplify mid to late week allowing
temperatures to gradually rebound. Overall no significant
precipitation events expected.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
Short Term...VFR this evening becomes MVFR after midnight, and
IFR or lower by Thu morning, with PL/FZRA at
KLEB/KHIE/KCON/KAUG. Could see a short period of PL at KMHT
around daybreak. IFR will persist through the day Thu into into
Thu night. May see some improvement toward daybreak, but may be
more likely Fri morning.
Long Term...Unsettled weather in the long term with a series of weak
surface lows and frontal boundary moving through the region. Periods
of MVFR/localized IFR conditions in scattered rain and snow showers
likely.
&&
.MARINE...
Short Term...Winds seas begin to pick pick up late tonight into
Thu with SCA expected through Thu night.
Long Term...Series of surface lows and frontal boundaries will favor
shifting winds over coastal waters in the long term. The
fluctuations will favor some light to moderate chop most days. Winds
speeds are projected to strengthen Monday behind a notable cold
front with strong small craft or possible gale conditions.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Winter Weather Advisory from 2 AM to 2 PM EDT Thursday for
MEZ012-013-018>020-033.
Winter Weather Advisory from 6 AM Thursday to 7 AM EDT Friday
for MEZ007>009.
NH...Winter Weather Advisory from 2 AM to 2 PM EDT Thursday for
NHZ006>011-015.
Winter Weather Advisory from 2 AM Thursday to 5 AM EDT Friday
for NHZ001>005.
MARINE...Small Craft Advisory from 6 AM Thursday to 8 AM EDT Friday for
ANZ150>154.
&&
$$
SYNOPSIS...Jamison
NEAR TERM...Cempa/Cornwell
SHORT TERM...Cempa
LONG TERM...Jamison
AVIATION...
MARINE...
Area Forecast Discussion
National Weather Service Lubbock TX
613 PM CDT Wed Mar 23 2022
.AVIATION...
Virga showers are beginning to come to an end at the terminals and
will be clear of the terminals by 01Z. Until then continue to
expect winds to be sustained around 20-25 knots with gusts to 40
knots. Winds will decrease by late evening and remain light
through the night. Expect VFR CIGs and VIS through this TAF cycle.
&&
.PREV DISCUSSION... /issued 155 PM CDT Wed Mar 23 2022/
SHORT TERM...
18Z upper air analysis reveals a compact vorticity lobe rotating
southward along the upstream periphery of a mid/upper-level cyclone
centered over the middle Mississippi River Valley, with the
vorticity lobe nosing its way into the northern TX PH. A secondary
yet lesser-defined shortwave perturbation was digging into northern
Chihuahua and the Big Bend region. At the surface, northwesterly
winds expand across the entire southern and central Great Plains
region, with a weak/diffuse, inverted, east-west oriented surface
trough located across far southwestern Kansas, the OK PH, and far
northern TX PH. The CWA remains far removed otherwise from any
viable surface boundary and/or front, as the dominant surface
cyclone is rotating across the Upper Midwest this afternoon. The
approach of the mid-level vorticity lobe has resulted in an increase
in moist, isentropic ascent throughout a shallow theta layer this
afternoon, evident by a field of small, turret-like cumulus rooted
above a dry and well-mixed sub-cloud layer with near-superadiabatic
lapse rates between the surface-to-3-km as per modified 12Z AMA RAOB
and RAP soundings. While the sub-cloud layer is very dry, i.e. T/Td
spreads of nearly 40 deg F at the surface (classic Inverted-V
thermodynamic profiles), a very low chance for sprinkles cannot be
ruled out in addition to gusty, erratic winds up to 50 mph owing to
the fast cellular movement governed by advection as the mid-level
jet streak near 50 kt moves overhead. The orientation of the
aforementioned Skew-T profiles will facilitate efficient downward
momentum transport for a) blustery, prevailing NWLY winds, and b)
enhancing the potential for a dry-microburst or two beneath any
convective shower. Convective showers will quickly wane in spatial
coverage towards evening given the loss of insolation, along with
prevailing winds diminishing altogether as the pressure gradient
relaxes as the mid-level vorticity lobe rounds the base of the
trough and ejects eastward.
Another cold night is ahead as the combination of a clear sky and
light winds enhances radiative cooling effects, with lows bottoming
out in the middle-upper 20s and lower 30s across the Caprock and
Rolling Plains, respectively. Temperatures may be a few degrees
colder, as low as the upper teens, in areas affected by terrain-
induced drainages. Northwesterly flow aloft will persist tomorrow as
the mid/upper-level trough axis moves over the Deep South, though
the geopotential height gradient will begin to slacken with NWLY
surface winds around 10 kt less than today. With the amplifying
mid/upper-level ridging to the west nearing the CWA, the gradual
rise in geopotential heights and a well-mixed boundary-layer through
~700 mb will result in temperatures climbing into the upper 60s and
lower 70s area-wide beneath a clear sky.
Sincavage
LONG TERM...
A sharp upper level trough currently over the central CONUS will
finally begin lose influence over the region on Friday. An upper
ridge behind this system over the western CONUS will slowly move
eastward through the weekend. This will send temperatures well above
seasonal averages from Friday through at least the first half of
next week. With a continued lack of rainfall through the time
period, fire weather concerns will undoubtedly increase yet again.
Temperatures look to soar to values on the order of 15-20 degrees
above seasonal averages with strong enough winds for at least
elevated fire weather concerns. Late in the weekend, an upper level
trough will move onshore on the west coast. However, it remains
unclear on how this trough will progress as it moves across the
Intermountain West early next week. Surface lee troughing will
develop late weekend as a result of this approaching trough which
will increase the surface winds into breezy category.
FIRE WEATHER...
Elevated to possibly critical fire weather conditions are expected
to develop tomorrow afternoon across the Caprock and Rolling Plains.
The combination of warm temperatures ranging from the upper 60s
across the extreme southern Texas Panhandle into the lower 70s
across the South and Rolling Plains; breezy, northwesterly winds at
around 15 mph at the 20 foot level, and minimum relative humidity
values between 8-12 percent will facilitate the potential for a few
hours of Red Flag conditions. However, spatiotemporal limitations
have precluded issuance of a Fire Weather Watch at this time. Winds
will diminish entirely after sunset Thursday with RH recovery
between 35-50 percent area-wide.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
51/99/99
Area Forecast Discussion
National Weather Service Marquette MI
638 PM EDT Wed Mar 23 2022
.SHORT TERM...(Through this evening)
Issued at 323 PM EDT WED MAR 23 2022
Ongoing event courtesy of an approaching low has proved to be
highly impactful and will continue to be so through the remainder
of this afternoon into early this evening. For locations from a
line somewhere near Crystal Falls/Iron River to Gwinn and
Marquette westward, SN has become the dominant precip type. It`s
expected to remain primarily SN through this forecast period,
with either a wintry mix or rain for locations eastward where
slightly warmer air aloft resides. Latest RAP 850mb analysis is
somewhat in line with what`s being observed across the U.P., with
those sub-zero Celsius temps west of Munising to Menominee. This
is forecast to not change dramatically through the next several
hours. Additionally, local effects will be in play as a more Nrly
component gets added to the wind, allowing for a LS influence to
become increasingly likely, notably in the upslope, higher terrain
areas of Marquette County into portions of the Keweenaw Peninsula.
But, with the synoptically-driven precip rotating along a SE to NW
axis, following the 850-700mb wind regime, this won`t necessarily
lead to significant impacts beyond what`s already covered within
the remaining time of the warning; more like localized periods of
enhanced precip. Temps will hover generally where they`re at
through the remainder of the daylight hours.
As for additional impacts to the ongoing power outage situation,
with ice and/or wet, dense snow weighing down trees, branches, and
power lines, it won`t take much wind to cause additional issues.
Folks should therefore be aware of and prepared for potential
power-related issues in the east and along the Lake Superior
shoreline, especially as that Nrly component at the surface
commences, for those who have thus far remained to have power.
.LONG TERM...(Tonight through Wednesday)
Issued at 344 PM EDT WED MAR 23 2022
The nearly-stacked 850-500 mb deep trough over the central
continental United States will shift northeastwards into Lower
Michigan this evening. Precipitation chances continue into the
overnight hours tonight as easterly flow maintains a deep moisture
profile into the Upper Great Lakes. Wind gusts near 30-40 mph are
expected into late this evening near Lake Michigan. These gusts
combined with the quarter of an inch to half of an inch of freezing
rain prompted an extension of the Winter Weather Advisory until 06z
Thursday.
As a shortwave ejects southward out of the primary closed mid and
low levels shifting northeastward, the winds aloft back
northeasterly late tonight across the U.P. Forecast sounding
analysis show most p-types shifting to snow with some slight chances
for sleet with this colder changeover by early Thursday morning.
A high amplitude, fast moving ridge extending north from high
pressure traversing through the Upper Mississippi River valley
region will bring an end to the precip chances by Thursday evening
across Upper Michigan.
A band of fgen supported precip is expected Friday out ahead of an
incoming colder Clipper. This will spread some light snowfall from
west to east Friday morning and through the evening. Gusty
northwesterly winds then begin to increase behind the low in the
late afternoon/early evening, but really increase in speed Friday
night. Communities along the Keweenaw and generally from Marquette
eastward towards Luce County could experience northwesterly gusts
from 30-40 mph Friday night and early Saturday associated with the
cold air advection.
Lake enhanced showers are favored in the northwest wind belts for
later Friday night and Saturday morning time period, then tapering
Saturday afternoon. Continued updates to PoPs away from the national
blend were made with this afternoon`s forecast for this time period.
At this time, a few inches of measurable snowfall is reasonable in
the favored NW wind belts from the earlier band and trailing lake
effect showers.
A seasonably-colder airmass sets up behind the Clipper for later
this weekend. Single digit temperatures are becoming more likely
Saturday night and below zero Sunday night, with daytime highs about
ten to fifteen degrees below normal on Sunday. The eastern U.P.
could see some additional lake effect showers in the north-
northwesterly wind belts into Sunday as well. Drier weather and
temperatures warming closer to normal are supported to start next
week as a synoptic ridge over the western continental US moves into
the central US early next week.
The WPC Ensemble Cluster tool begins to show widely diverging
solutions for the middle of next week as a general mean trough sets
up over central CONUS. There is wide solutions on the depth,
placement and type of trough though. The end result is fairly low
confidence in the resultant impacts for the Upper Michigan for next
Tuesday and Wednesday and something to keep an eye on.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 638 PM EDT WED MAR 23 2022
LIFR/VLIFR conditions will persist at the terminals tonight.
Conditions will improve slowly on Thu at all sites.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 344 PM EDT WED MAR 23 2022
East gales up to 40 knots across the eastern lake this afternoon
shift northeast this evening with continued northeast gales in the
western lake. Northeast winds 20 to 30 knots tonight diminish below
20 knots Thursday morning and remain weak through Friday morning.
Northwest winds of 20 to 25 kts spread across the lake Friday
evening and strengthen to 40 kt gales Friday night, mainly across
central and eastern portions of the lake. Northwest gales to 35
knots continue across the eastern lake through Saturday afternoon.
Northwest winds 25-33 knots in the eastern lake decrease below 20
knots Sunday evening. Patchy heavy freezing spray is possible Friday
night into Saturday morning and then becoming more widespread in the
eastern part of the late Saturday and through Sunday morning.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Winter Weather Advisory until 8 PM EDT this evening for MIZ006-
007-085.
Winter Storm Warning until 8 PM EDT /7 PM CDT/ this evening for
MIZ001>005-009>011-084.
Winter Weather Advisory until 2 AM EDT /1 AM CDT/ Thursday for
MIZ012>014.
Lake Superior...
Gale Warning until 8 PM EDT /7 PM CDT/ this evening for LSZ162-
263.
Lake Michigan...
None.
&&
$$
SHORT TERM...lg
LONG TERM...NLy
AVIATION...07
MARINE...NLy
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Morristown TN
807 PM EDT Wed Mar 23 2022
.UPDATE...
EVENING UPDATE.
&&
.DISCUSSION...
The Wind Advisory has been allowed to expire as wind gusts have
dropped below advisory levels, and will continue to fall over the
next few hours. Showers have ended in our area, and PoPs will be
cut back, but a low to slight chance will be kept in NE sections
as the HRRR hints at some redevelopment in that area before
midnight.
DGS
&&
.AVIATION...
00Z TAF DISCUSSION.
VFR conditions will continue through the period for all sites. Gusty
winds will continue at the TAF sites for a few more hours. Gusts
should drop off at all sites by midnight, with winds remaining at
7-10 kt through the night. Tomorrow, winds will increase again in
the afternoon, with gusts of 20-25 kt expected.
DGS
&&
.PREV DISCUSSION...
/ISSUED 335 PM EDT Wed Mar 23 2022/
SHORT TERM...(Today through Tomorrow)
Key Messages:
1. Isolated showers and thunderstorms are possible this
afternoon. Some of these storms could be strong.
Discussion:
Currently isolated showers and thunderstorms are moving northeast
across Tennessee into Kentucky and Virginia. Some of the stronger
storms have had hail, and gusty winds, and some broad rotation
associated with them. Based on mesoanalysis and CAMs the best
environment for storms in east TN is quickly dwindling as the jet is
weakening and moving off to the north and east. While the low level
shear has been very strong it`s mostly been unidirectional which
isn`t allowing most of these storms to maintain and mature. A
slightly better environment exists across West Virginia into
Virginia where diurnal heating has been going on for longer... And
as some of these storms move into this better environment they could
possibly restrengthen, but most likely this will occur further into
KY/WV.
The more widespread weather event today has been the breezy winds
being mixed down to the surface. Numerous weather stations across
the region are reporting sustained winds of 20-30mph and gusting
over 40mph. The temperatures today have been very warm (some
locations reaching over 80) and we`re experiencing very good mixing
of the LLJ winds down to the surface. A Wind Advisory is in effect
through 8pm EDT when the winds should begin to decouple and the core
of the LLJ moves out of the area.
Once the isolated storms move out this afternoon, and the LLJ
vacates the area weather should quiet down for tonight into
tomorrow. We could see a few patchy areas of fog overnight in
locations that received rain this afternoon and possibly clear out
overnight. Temperatures will be cooler tomorrow without the jet
bringing in the warm air from the south.
ABM
LONG TERM (Friday through Wednesday)...
Key Messages:
1. Chilly Friday and through the weekend. Freezing temperatures
possible at many locations Saturday night / Sunday morning.
2. Rapid warming starts Tuesday.
3. Storms possible Day 8 (next Thursday).
Discussion: In sum, a western U.S. ridge / eastern U.S. trough
pattern will hold until Monday, when a deep trough quickly moves
into the Rockies. Then the models diverge.
So, our troughing for Friday-Saturday will bring our area cool
temps and an unsettled pattern that will see a few areas of
light precipitation (mostly liquid). The eastern ridge will then
move off the east coast, and so while we will continue under cool NW
flow for Sunday/Monday, it will be generally dry.
Our transition to ridging aloft will net a rapid warm-up Tuesday,
with chances for showers north for Tues, and areawide for Wed.
This however is where the model divergence comes in. The 12Z GFS is
more progressive with the Rockies trough, moving it into the central
plains states Wed, while the Canadian and ECMWF dig the trough into
northern Mexico and Texas. The winner of these two solutions will
determine the timing of the mid-week precip. NBM is going with
chance POPs Wednesday with this storm system, but the latest 12Z
extended models all agree on holding off precip onset until
Thursday, with GFS the earliest (early Thurs morning), the ECMWF
Thursday noon, and the Canadian Thurs evening. It is common for
Rockies troughs to slow down as model runs progress, so precip onset
and conclusion is surely going to need updating. As it stands, the
forecast by us and our surrounding offices will carry chance POPS
(30 pct) for Wed until more clarity is possible. But I think Wed
will end up being a nice day before the possible Thursday storm
system.
GC
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 43 63 43 59 41 / 0 0 0 0 0
Knoxville McGhee Tyson Airport, TN 44 62 43 56 40 / 10 10 0 10 10
Oak Ridge, TN 43 62 42 56 40 / 10 0 0 10 10
Tri Cities Airport, TN 45 63 40 52 37 / 30 10 0 30 40
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
Area Forecast Discussion
National Weather Service Blacksburg VA
949 PM EDT Wed Mar 23 2022
.SYNOPSIS...
Scattered showers and a few thunderstorms look to continue through
tonight as a cold front pushes through the region. This is the
first of a series of fronts that will deliver cooler air and
continued shower chances heading into the start of the weekend.
Drier conditions are expected to return with high pressure early
next week.
&&
.NEAR TERM /THROUGH THURSDAY/...
As of 840 PM EDT Wednesday...
A cold front brings additional showers and even a few
thunderstorms to the region tonight. Drier conditions Thursday...
Overall the current forecast package remains on track with some
subtle changes to temperatures, dewpoints, and precipitation
coverage heading into the remainder of the evening and overnight
period. So far, we have managed to miss severe weather to our west
across West Virginia near the cold pool of the occluded low and down
to our south across the Carolinas along an old stationary boundary.
The wedge remains our friend for now in keeping us fairly stable and
limiting any convective concerns. Some signs of erosion in the wedge
have been noted off to our west across extreme western Virginia and
southeast West Virginia. This trend looks to continue as south to
southeasterly flow picks up ahead of an approaching shortwave
trough/cold front that looks to push through overnight into early
Thursday morning.
With that said, the thunderstorm threat looks to remain with us over
the next two to three hours. Currently a pool of convection
continues to stream north from northern Georgia and western South
Carolina. Warnings have been prompted with this area as it surges
across the western mountains of North Carolina from Boone, NC south
toward Asheville, NC. The latest NAMnest and HRRR guidance continues
to enhance this convection as it pushes north along the Blue Ridge.
CAPE values in these areas continue to hover between 500-1000 j/kg
with bulk effective shear values along a gradient around 65-75 kts.
This will be our storm fuel for this evening with damaging winds and
the potential for an isolated tornado as the primary threat,
especially in areas along the southern extent of the Blue Ridge. For
that reason a Tornado Watch is in effect for the southern Blue Ridge
from now through midnight. On top of the severe weather
concerns comes the risks for localized flooding due to storms
training over some of the same areas. Rainfall in these areas
has already exceeded one to two inches over the last 24 to 48
hours. Areas outside of the Blue Ridge have seen amounts upwards
of a quarter of an inch to three quarters of an inch throughout
the last 36 hours. Luckily for us no widespread flooding is
likely due to the antecedent dry conditions.
All of this is in advance of a cold frontal boundary that will
steadily push east from West Virginia and eastern Kentucky tonight.
The front will be driven by additional shortwave troughs rotating
around a deep upper level trough that encompasses much of the
eastern two-thirds of the country. This trough will gradually
kick out of the region later in the week, but until then it will
be a continuation of front after front until the weekend. As of
now our cold front tonight should push into southeast West
Virginia, the New River Valley, Mountain Empire, and ALleghany
Highlands between now and midnight Thursday. From there the
front will gradually inch east toward the Roanoke Valley, North
Carolina foothills, and Piedmont late Thursday morning into
Thursday afternoon. Precipitation should decrease in coverage (and
intensity) from west to east later tonight through Thursday
mid- morning as the front traverses the area.
A lull in the wet weather looks to occur Thursday afternoon into
Friday. The exception of this will be over the mountains where
additional showers are likely as another piece of shortwave energy
rolls through.
Overnight lows tonight will fall into the 40s over the mountains to
the 50s further east into the Piedmont in advance of the front. We
rebound with a little more sunshine in the wake of our front
Thursday. South to southwesterly flow gets temperatures back
into the low to mid 60s over the mountains to upper 60s and low
70s further east.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
As of 200 PM EDT Wednesday...
Light showers mostly in the mountains, and some snow this
weekend for Southeast WV...
Behind a cold front on Thursday night, an upper trough and cooler
air will move in to the area. This will allow for some stronger
westerly winds and a bit of upslope rain Friday afternoon and
evening. A much deeper upper trough and reinforcing cold front will
arrive overnight Friday into Saturday morning. Chances for rain will
spread to the Blue Ridge throughout the day Saturday, as this upper
trough will pass much closer to us than the Thurs/Fri trough. As the
the coldest air of the week so far is pulled into the CWA, below
freezing temperatures will be found in mountain areas. This will
lead to snow restricted mostly to Western Greenbrier County, WV
overnight Saturday into Sunday. Localized accumulations of 1-2" are
possible, but the vast majority of folks that see any flakes will
get a dusting up to an inch.
Temperatures during this period will be around normal during the
daytime, but after the cold front Friday night, temperatures
overnight will plummet to near freezing in the east, and solidly
below freezing west of the Blue Ridge. Little recovery in warmth is
expected Sunday as we remain in northwest flow and high pressure is
advected into the area from the northwest.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 130 PM EDT Wednesday...
Broad upper level northwest flow follows behind the weekend
system, as high pressure begins to move into the Mid Atlantic
around the beginning of next week, before transitioning to a
more westerly direction. Temperatures will begin to warm up
compared to the cooler weekend temperatures. Dry conditions are
expected through Monday, before the arrival of a warm front
moving northward towards the area. This front will likely bring
another round of mid-week precipitation for Tuesday into
Wednesday. However, there is not much agreement between models
on the timing and extent of the precipitation.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
As of 0950 PM EDT Wednesday...
...Sub VFR conditions continue overnight into Thursday morning as
showers and thunderstorms push through...
Shower and thunderstorm activity continues to slowly push through
the area this evening as a cold front pushes in from the west. The
bulk of the activity remains from KROA/KLYH south to KBCB/KMTV and
KUKF. This area continues to see a mix of MVFR and IFR cigs/vsbys as
heavier showers push through. Some thunderstorm activity has
also been mixed in with a few flickers of lightning at both
KBCB, KTNB, KROA, and KLYH. The thunderstorm threat has
decreased at most of the TAF locations with the exception of
KLYH where a TEMPO has been left in for the next 3 hours as
convection continues to push through. Elsewhere VFR conditions
remain to the west at both KBLF and KLWB as well as to the east
toward KDAN. These areas will also see shower activity overnight
into Thursday morning as the front pushes through. Any shower
or thunderstorm activity looks to quickly come to an end between
05z/1am and 07z/3am Thursday morning.
Despite the precipitation ending and the front gradually
pushing through, low cigs/vsbys will remain at most of the
terminals. MVFR to IFR flight categories are expected through
at least 12z/8am Thursday morning as our cold front is slow to
move east. It`s not until after 16-18z/12-2pm that most
locations return back to VFR.
Winds will remain out of the south and southwest tonight at 5 to 15
kts with gusts upwards of 20 to 30 kts along the higher ridges along
and west of the Blue Ridge Parkway. Winds will switch toward more of
a westerly direction behind the front Thursday morning into Thursday
afternoon. Speeds once again will be between 5 to 15 kts with gusts
upwards of 15 to 25 kts along the ridges by Thursday afternoon.
Extended Aviation Discussion...
VFR conditions will remain for most with the exception of the
mountains through Friday morning. Sub VFR conditions make a return
with our next cold front Friday afternoon into Saturday morning.The
front clears the area late Saturday into Sunday as high
pressure returns. VFR conditions kickoff the start of the new
workweek.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...ET
NEAR TERM...DB/ET
SHORT TERM...VFJ
LONG TERM...AS
AVIATION...ET
Area Forecast Discussion
National Weather Service Topeka KS
546 PM CDT Wed Mar 23 2022
...AVIATION UPDATE...
.DISCUSSION...
Issued at 304 PM CDT Wed Mar 23 2022
KEY MESSAGES
- Rain/snow showers through tonight (no snow accumulations)
- Slow warmup through early next week
- Precipitation may return by the middle of next week
This afternoon, a highly amplified pattern continues to dominate the
CONUS, highlighted by ridging over the Rockies and the Atlantic, and
a deep trough from the Southern Plains to the Great Lakes. Beneath
the upper trough, a deep SFC cyclone was located over the Upper
Midwest, with a broad, and moist, cyclonic flow dominating the
region. Within this flow, a few embedded waves are rotating south
across the region, each with an enhancement to shower activity. One
such wave is moving south out of Nebraska/Iowa this afternoon, and
will bring a modest uptick in shower activity across northeast
Kansas through tonight as it pivots through the area. Despite
temperatures in the upper 30s to low 40s this afternoon, wet-bulb
temps are in the low to mid 30s, and forecast thermal profiles
suggest temps aloft are plenty cold enough to support a rain/snow
mix, or even all snow at times, even with marginal SFC temps. mPING
reports across the area support this as well. Snow accumulation is
not expected, but a rain/snow mix can be expected through tonight
where showers occur.
On Thursday, subsidence aloft and drier low-mid level air attempting
to work into the area should lead to a gradual clearing of the low
clouds from west to east by mid to late afternoon. Although, there
may be enough lingering low-level moisture to support scattered
afternoon cumulus development in the wake of any morning clearing,
which may temper highs just a touch.
On Friday, an upper wave will move through the Great Lakes, glancing
the Mid-MS Valley region. While significant impacts are not
expected, a cold front will move through with gusty winds and cooler
temperatures. Because of the glancing nature of the upper wave, the
SFC front will lose upper level support and basically get hung up to
our west and south over the weekend. With NE Kansas being on the
"cooler" side of that boundary, model guidance have trended cooler
FRI-SUN in the developing E/SE low-level flow. Aloft, a fairly
prominent baroclinic zone looks to setup NW to SE across the
Central Plains. Synoptically, NW flow atop a stalled baroclinic
zone can be a great setup for convection, especially later in the
spring and summer. However, with early spring moisture and
instability, it appears the risk of showers or storms should
mostly be muted, but the risk isn`t zero. For now, we`ll continue
to keep the forecast dry, but something to watch as some model
guidance hint at some shower potential Sunday into Monday. At
minimum, there may be a little more cloud cover around at times.
With time, the baroclinic zone should lift NE into the Upper Midwest
as a more prominent west, or southwest, flow aloft develops early
next week, favoring strengthening WAA and an increased southerly
flow. This should lead to a quicker warmup early next week and the
forecast reflects this expectation. Should the SFC front remain
to the south, though, temps may end up not as warm early next
week.
By the middle of next week, significant differences show up in
model guidance with the evolution of troughing attempting to
redevelop from the Rockies into the central CONUS. Generally
speaking, there appears to be decent support for a cold front
passage Tuesday or Wednesday with a quick shot of colder air, and
possibly another risk of precipitation.
Martin
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday)
Issued at 546 PM CDT Wed Mar 23 2022
Moisture wrapped around the low pressure system over the Upper
Midwest is forecast to keep MVFR CIGS over the terminals and
northeast KS until late in the period. CIGS may improve
temporarily at MHK, but the latest forecast soundings from the
RAP show the lower CIGS moving back in. There is likely to be
some -RASN with the radar returns moving south through the area.
This should have limited impact at the ground but would likely
pose some low level icing concerns. The precip is forecast to fall
apart shortly after 06Z tonight.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...ICT/Martin
AVIATION...Wolters