Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/03/24
Area Forecast Discussion
National Weather Service Boston/Norton MA
738 PM EDT Thu May 2 2024
.SYNOPSIS...
A weak low pressure will bring scattered showers near the coast this
afternoon. Northeast onshore flow will bring cloudy and cool
conditions tomorrow. High pressure supplies dry weather with
cooler onshore breezes on Saturday. Increasing clouds later
Saturday into Sunday, with solid chances for rains and cooler
temperatures on Sunday into Sunday evening. High pressure then
brings dry and seasonable weather early next week, with our next
chance for rains after Sunday not appearing until Wednesday.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
733 PM Update:
Though it is dry into central and western MA and much of
northern CT and adjacent RI. However it`s a different story in
eastern MA as a combo of diurnal heating and dynamic
ascent/midlevel diffluence owing to a potent shortwave
disturbance digging southeast from central NH is responsible
for a cluster of scattered low-topped convective showers, and a
few have deepened enough to produce lightning and some pea/BB-sized
hailstones. We`re approaching sundown now, and that should start
to diminish the potency of these heavier showers/embedded
t-storms, but we still expect scattered showers to continue to
progress southeast towards south coastal MA and the Cape and
Islands through 9 PM, following HRRR guidance. Adjusted PoP/wx
to change weather to areal coverage wording.
Thereafter the story turns to returning stratus and fog, with
northeast flow drawing the ongoing area of stratus over NH/ME
SSW across much of SNE through the late evening and overnight
hours. BUFKIT soundings shows the stratus layer lingering into
the Friday morning hrs.
Previous discussion:
Shortwave trough aloft continues to dig south into SNE this
afternoon. With clouds clearing across much of northeast MA, this
could set the stage for an isolated pop up shower with a low chance
at a rumble of thunder. SPC mesoanalysis is showing around 100
J/kg of CAPE/instability in northeast MA this afternoon. Showers
quickly move south with the passage of a back door cold front.
This back door cold front will switch our winds to the NE
bringing cool air and a low level marine stratus cloud deck over
the region tonight. This cloud deck will keep lows mild again
overnight only dropping into the upper 40s.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
Rising heights and high pressure building in will attempt to erode
the marine status deck tomorrow from west to east, but will
likely linger well into the afternoon for the Cape and Islands.
Best chance for sun tomorrow will again be in the CT River
Valley which is where high temps could top 70F. Elsewhere, cool
onshore easterly flow will keep highs in the upper 50s to low
60s.
Upper level ridge axis passes over SNE Friday night with high
pressure directly overhead. Winds become light and variable and
skies should begin to clear as onshore flow weakens. This could
allow for overnight temps to drop into the low 40s, with an
outside shot at upper 30s.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Highlights:
* Increased clouds but dry Saturday, but cooler with better chances
for rains Sun into Sun night.
* Mainly dry Mon and Tue with seasonable to slightly above normal
temps.
* Warm front around Tue night or Wed brings next chance for clouds
and showers.
Details:
Saturday and Sunday:
Sfc ridge of high pressure over coastal New England to very slowly
weaken/shift eastward through the course of the weekend. Meanwhile
on the western periphery of upper level ridging over western New
England and the northern mid-Atlc and associated with pretty
disorganized shortwave trof energy, warm advection driven showers
will gradually shift eastward into Southern New England, mainly
during the latter half of the weekend (Sunday).
Still looks like Saturday is the better day of the two, although
will have cooler breezes near the coast and increased cloud cover in
all areas. Highs should reach the 60s for most interior locales, but
around the mid 50s along the eastern MA coast, with upper 50s/around
60 near the southern coastline.
Sunday on the other hand looks cloudy with periods of rain showers,
which slowly shift offshore during the evening and overnight. There
are some indications that the frontal boundary responsible for the
rains slows/stalls offshore that could keep chances for showers
going well into Sunday night but this isn`t set in stone. Though
expected rain amts aren`t substantial, should be a pretty soggy day.
Despite the warmer air aloft, cooler highs in the 50s given the
cloud cover, rains and limited mixing. Milder-than-climo on the lows
with the continued cloudiness in the mid to upper 40s.
Monday and Tuesday:
For Monday...could still see some leftover light showers into the
morning across southeast MA and the Cape and Islands as frontal
boundary in vicinity slowly sags southward. ECMWF in particular is
slowest to progress the front offshore. Ridging to the north and
west eventually builds into Southern New England later in the day
and especially into Monday evening. Highs in the 60s to lower 70s
and lows in the mid 40s to lower 50s.
For Tuesday...high pressure brings a period of cooler onshore flow
to coastal New England, with temperatures being significantly milder
inland away from the maritime influence. Kept highs in the 60s near
the coast with highs inland into the lower to mid 70s, with
potential spot 80 degree readings not out of the question in the
warmer spots in the CT Valley. Increasing clouds for Tue night ahead
of a warm front but associated rains should hold off until Wed.
Wednesday:
Warm front associated with a rather strong area of low pressure over
the northern Plains drapes itself over or just west of SNE. This
offers the next best chance for rains after Sunday with PoPs in the
medium (30-40%) range for rains on Wednesday.
&&
.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
Forecast Confidence Levels:
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
00z TAF Update:
Tonight: High confidence in trends, though moderate on timing.
Ongoing area of SHRA/embedded TS over eastern MA to progress
southeast toward Cape Cod airports by 02z, then moving offshore.
Brief/temporary restrictions possible at BOS and the Cape
airports with brief MVFR visby and occasional lightning.
Otherwise, VFR to then deteriorate to IFR/LIFR ceilings as
stratus over NH/ME spread SSW. Expect stratus to develop by
01-02z over the North Shore MA and then spread SSW through the
evening and overnight. Ceilings at BAF/BDL likely more in the
MVFR range, while IFR-LIFR should be more common for eastern and
central airports. Stratus likely to persist well into the AM
hrs. NE winds around 8-12 kt.
Tomorrow: Moderate Confidence
Gradual improvements in CIGS back to MVFR late morning, then to
VFR in the afternoon with the CAPE and Islands seeing IFR
linger longer into the day. Winds turn SSE at 5-10 knots
Tomorrow Night: High Confidence
VFR with light and variable winds.
KBOS TAF...Moderate confidence. SHRA/occasional TS with brief
visby restriction should exit southeast from BOS by 01z. VFR
then becomes IFR-LIFR as soon as 01z but more likely after 02z
as stratus sets in from NH/ME. NE winds around 10-12 kt.
KBDL TAF...Moderate confidence. VFR for most of the first half
of the night, with MVFR stratus developing late overnight into
the pre-dawn hrs. Low prob of IFR ceilings. N winds around 10
kt.
Outlook /Saturday through Tuesday/...
Saturday: VFR. Chance SHRA.
Saturday Night: Mainly VFR, with local IFR possible. Chance
SHRA.
Sunday: Mainly VFR, with areas IFR possible. Breezy. Chance
SHRA.
Sunday Night: MVFR/IFR conditions possible. Breezy. Chance
SHRA.
Monday: Mainly VFR, with local MVFR possible. Chance SHRA.
Monday Night through Tuesday: VFR. Slight chance SHRA.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Tonight: Moderate Confidence
Weak low pressure system will cause scatted rain showers with
isolated thunder this afternoon and evening mainly across the
eastern waters. Cool NE flow will cause a low status/fog cloud deck
to form this evening. Winds will approach 20-25 knots esspically
across the southern waters between 06-12z tonight, but confidence
was not high enough to issue a small craft advisory at this time.
Tomorrow: Moderate Confidence
Low status and fog stick around into the afternoon before possibly
clearing in the evening. Winds become light and variable tomorrow
Tomorrow night: High Confidence
High pressure overhead will keep conditions dry with light and
variable winds
Outlook /Saturday through Tuesday/...
Saturday: Winds less than 25 kt. Slight chance of rain showers.
Saturday Night through Sunday: Winds less than 25 kt. Chance of
rain showers.
Sunday Night through Monday: Winds less than 25 kt. Seas
locally approaching 5 ft. Chance of rain showers.
Monday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Slight chance of rain showers.
Tuesday: Winds less than 25 kt. Slight chance of rain showers.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.
&&
$$
SYNOPSIS...Loconto/KP
NEAR TERM...Loconto/KP
SHORT TERM...KP
LONG TERM...Loconto
AVIATION...Loconto/KP
MARINE...Loconto/KP
Area Forecast Discussion
National Weather Service Dodge City KS
603 PM CDT Thu May 2 2024
.KEY MESSAGES...
- Strong to marginally severe thunderstorm complex is expected
Friday night, favoring the northeast half of our area.
- Strong weather system early next week will likely only bring
precipitation to the far northeast/eastern zones Monday, while
all other zones are dry-slotted.
- Generally quiet weather Tuesday/Wednesday with above normal
temperatures.
&&
.SHORT TERM /THROUGH FRIDAY/...
Issued at 200 PM CDT Thu May 2 2024
Water vapor satellite imagery and RAP upper air analysis reveal
broad, longwave troughing is in place west of the Mississippi
River, with multiple embedded shortwave troughs, and longwave
ridging to the east. At the surface, observations show strong
northerly winds across southwest KS behind last night`s cold
front. These winds are drawing much cooler air equatorward this
afternoon, resulting in highs in the low to mid 70s. Tonight,
winds will weaken substantially as surface high pressure moves
into the central plains, and combine with partly cloudy skies to
support at least modest radiational cooling fostering lows
dropping into the 40s.
Daytime Friday, short range guidance agrees an upper level
shortwave trough will dig east-southeast from the northern
Intermountain West into the north-central Rockies. Ahead of this
feature, a surface lee cyclone will develop and deepen over
eastern CO, causing south to southeasterly winds to increase
over southwest KS in response. However, any warming effect these
winds have will be somewhat offset by at least partly cloudy
skies, and afternoon temperatures will only be marginally warmer
than today with highs in the mid to upper 70s.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 200 PM CDT Thu May 2 2024
At the beginning of the long term period, medium range ensembles
agree the above mentioned shortwave trough will continue east to
the northern plains, sending a cold front southward through our
area. There is strong ensemble support for this frontal passage
being accompanied by an MCS, with the ECMWF EPS and GEFS both
show probability of QPF > 0.1" in the 50-80% range for at least
the northeast half to 2/3rds of our area. Additionally, this MCS
may be marginally severe given 35-45 kts of deep-layer shear,
although meager instability (CAPE < 600 J/Kg) should limit
severe coverage.
Over the weekend, medium range ensembles show a powerful upper
low moving onto the western coast and into the Intermountain
West by 00Z Monday. A few weak, lead shortwaves may eject out
of the Desert Southwest into the central plains bringing a
chance for precipitation across our area, but confidence is not
high, and pops were limited to the slight chance (15-24%) to
chance (25-54%) categories. Otherwise, temperatures will hover
around normal (low-mid 70s) with afternoon highs in the mid 60s
to low 70s Saturday to the low to mid 70s Sunday.
Early next week, ensembles eject the significant, negatively-
tilted upper level trough onto the High Plains daytime Monday.
The timing/location of this trough by 00Z Tuesday suggests
southwest KS will be mostly dry-slotted by this wave, with
strong westerly winds, warm temperatures, and fire weather
prevailing. That said, the far northeast/east zones may get
lucky with some afternoon showers/thunderstorms, but confidence
is not super high as ECMWF EPS and GEFS probability of QPF >
0.1" is only in the 20-40% range. Once this wave passes, the
remainder of the long term period appears quiet as ensembles
show southwest KS will sit on the southern periphery of longwave
troughing centered over the northern plains. Temperatures will
be 5-10 degrees above normal with afternoon highs in the upper
70s to mid 80s.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 601 PM CDT Thu May 2 2024
VFR flight category for all terminals during the time period.
Winds will increase after 16z to sustained 15-20 kts with gusts
in the 25-30 kt range.
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...Springer
LONG TERM...Springer
AVIATION...Tatro
Area Forecast Discussion
National Weather Service Fort Worth TX
803 PM CDT Thu May 2 2024
...New Short Term, Aviation...
.SHORT TERM... /NEW/
/This Evening through Saturday Morning/
A fairly uneventful afternoon has ended, and dryline convection
has started in full swing to our west. The storms currently
ongoing as of 8 PM are fairly slow moving, and do not look to
enter our western Big Country counties until closer to 9 PM. While
CAM guidance over the afternoon has been fairly off-kilter in
regards to storm initiation, the 23Z HRRR finally has a good
handle on it. Over the rest of the evening, expect scattered
storms to form off the dryline and move east, eventually moving
into areas near and west of US-281. Forecast parameter space shows
this environment has the lapse rates, shear, and instability
present for large hail and damaging winds. The tornado threat is
on the lower side due to overall unfavorable low-level shear
magnitude, but we cannot rule out an isolated tornado as these
storms continue into our area tonight.
Further north in Oklahoma, a weak front will continue to advance
southward, moving through North Texas overnight. Additional
chances for showers and storms are expected mainly across our
eastern counties, with the bulk of the activity likely further
into Arkansas. The front will wash out as surface winds across the
region shift east. Expect not much change for the sensible
weather, with little in the way of cold advection. Overnight
temperatures will be isolated by nocturnal stratus, bottoming out
once again in the 60s.
NAMNest and HRRR guidance continue to highlight a cluster of
showers and storms over southeast Central Texas late in the
morning. With our southeastern counties having already experienced
pretty considerable flash flooding, the re-aggravation of prior
flooding will need to be watched through tomorrow afternoon. This
will be especially true for Limestone, Freestone, and Leon
counties, where up to around 5-7" of rain has fallen in the last
several days.
By tomorrow afternoon, south-southeast flow will have been re-
established across the region, aiding in the potential for warm
advection showers and storms. The location of these storms will be
highly dependent on where lingering outflows set up tonight, so
have blanketed the region in at least isolated storm chances.
Later in the afternoon, dryline convection is once again expected
to our west, moving east like the days before. Potential for
severe-caliber hail and winds is expected with any stronger storm,
while the tornado threat remains on the lower side due to
unfavorable low level wind profiles. Current longer-range CAMs
have really backed off on any established linear lines/clusters
moving through. The HRRR remains the more pessimistic model, with
clusters moving towards I-35 tomorrow night, and weakening as they
move into East Texas. With how well the CAMs have been resolving
the actual event lately, this will be a wait-and-see game once
they initiate tomorrow.
Going into Saturday morning, expect another warm night in the 60s
with cloudy morning skies.
Prater
&&
.LONG TERM... /Issued 216 PM CDT Thu May 2 2024/
/Friday Night and Beyond/
Scattered thunderstorm development is likely along the dryline
west of our forecast area late Friday afternoon. Initial activity
will likely take on more discrete/semi-discrete supercellular
structures capable of producing all storm hazards. It is a bit
uncertain how far east this convection maintains into our area,
but a majority of the CAM guidance keeps at least a low end severe
weather threat along/west of Highway 281 late Friday evening
lessening in intensity as this cluster/broken line of
thunderstorms approaches the I-35 corridor during the overnight.
The Thursday cold front will push back south toward North Texas
Saturday morning with most medium-range guidance suggesting the
frontal boundary will stall somewhere north of I-20 by Saturday
afternoon. This boundary will provide a source of lift for
scattered shower and thunderstorm development in a continually
moisture-rich environment during the day Saturday. With the front
acting as a focal point for thunderstorm development, the greater
rain chances (50-60%) will settle generally along/north of I-20
Saturday.
Confidence is increasing in a more widespread, impactful rainfall
event Saturday night into Sunday as guidance continues to suggest
a potent, compact mid-level shortwave will shift over this
stalled frontal boundary. Deep moisture and more than sufficient
instability will likely allow for thunderstorm development near
the triple point located in West Texas late Saturday
afternoon/evening. An increasing 30-40 kt low-level jet will
provide the needed warm/moist advection to maintain this activity
into our forecast area Saturday night and may lead to additional
development ahead of this complex across North and Central Texas.
The primary threats will be heavy rainfall, large hail, and
damaging winds. However, backed surface winds, low LCLs, and some
low-level curvature in forecast hodographs highlight at least a
low end potential for tornadoes as well, especially west of I-35
as this activity enters our forecast area. Additional thunderstorm
development is possible Sunday afternoon but will be largely
dependent upon the position of frontal boundaries and any
lingering outflow boundaries.
Ensemble guidance continues to highlight another storm system
entering the Plains in the Monday-Tuesday timeframe. This could
bring chances for storms back to North Texas, however the best
synoptic-scale lift looks to remain north of our forecast area as
of now. By the middle of next week, low-level southwesterly flow
and a building upper-level ridge over the Gulf Coast region will
allow for afternoon temperatures to rise into the mid-80s to low
90s by the Tuesday/Wednesday timeframe next week. Keep up with the
forecast over the next several days as we further refine the
details of this messy, mid-spring weather pattern!
Langfeld
&&
.AVIATION... /NEW/
/00Z TAFs/
VFR and southerly winds will prevail through the rest of this
evening. MVFR cigs will surge northward late tonight, moving over
and ACT around 05Z and D10 closer to 09Z. A weak front will move
through D10 after midnight bringing a chance for surrounding
showers/storms and east/northeast winds around 5 kts. Conditions
will continue to deteriorate, with IFR cigs expected at ACT near
daybreak and slightly reduced visibilities at all sites due to
mist. There are lower chances for IFR cigs at D10, but are much
higher further south. Additionally, just after daybreak, there are
low probs for LIFR cigs at ACT, but are too low to include.
Tomorrow afternoon, ceilings will lift back to VFR closer to 22Z
with southeasterly winds returning.
There are chances for late morning and afternoon convection
tomorrow, but location is highly dependent on where leftover
outflow boundaries and the weak front ends up. Model guidance
continues to be in misalignment, and with this uncertainty on
location, have refrained from a prevailing weather group at this
time. This will be refined in further TAF issuances.
Prater
&&
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 66 83 69 82 68 / 60 20 30 60 60
Waco 66 82 69 80 68 / 40 30 20 40 50
Paris 64 81 66 80 65 / 50 30 20 60 50
Denton 63 82 66 81 66 / 70 20 30 60 70
McKinney 65 81 66 80 68 / 60 20 30 60 60
Dallas 67 83 69 82 68 / 60 20 20 60 60
Terrell 65 81 67 82 67 / 60 30 20 50 50
Corsicana 67 83 69 83 69 / 50 30 20 40 50
Temple 66 83 69 82 68 / 40 30 20 30 40
Mineral Wells 63 82 66 82 66 / 70 20 30 60 80
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Grand Rapids MI
1052 PM EDT Thu May 2 2024
.KEY MESSAGES...
- Showers and thunderstorms into Friday
- Mild with several chances for showers/storms
&&
.UPDATE...
Issued at 1051 PM EDT Thu May 2 2024
Core of the instability has remained south of the forecast area
this evening. With the loss of daytime heating, the instability
has weakened and we do not expect a resurgence into the area
tonight. The RAP model only shows 100-400 j/kg of MUCAPE
overnight. So, we expect rain showers tonight with the potential
of isolated thunderstorms. The HREF continues to show pockets of
heavier rain developing ahead of the cold front that will move in
late from Wisconsin. Given the HREF has been consistent in showing
some half inch to one inch amounts there is a fairly high
confidence in this occurring from MKG northeast through RQB and
CAD especially. It will take much of the day on Friday for the
front to clear southeast portions of the forecast area near JXN.
&&
.DISCUSSION...
Issued at 304 PM EDT Thu May 2 2024
- Showers and thunderstorms into Friday
An upper level wave in the Upper Plains will track into the
Western Great Lakes tonight. It takes on a negative tilt as it
does. At the same time a low level jet will be tracking
northeastward through Western Lower MI, generating lower level
lift. Elevated instability will be present and PWAT values climb
to well above normal levels at around 1.5 inches. Given the
moisture, deep lift and presence of instability, showers and
thunderstorms will become numerous tonight. High res models
suggest several pockets of higher wind gusts could evolve
overnight, but most indications are that they may struggle to
reach severe criteria. The latest HRRR indicates the storms
developing around Chicago will build northeast and into our CWA
later this afternoon and into the evening. We did increase POPs
accordingly.
On Friday the front will be pushing eastward through the CWA by
mid afternoon. Thus any shower/storm activity will decrease from
west to east through the early to mid afternoon hours. At this
time the instability is progged to be limited so severe weather is
not anticipated.
- Mild with several chances for showers/storms
A persistent long wave trough over the Rockies will send a steady
stream of short waves toward the Great Lakes through the period.
Southwest winds aloft will also ensure that warm air flows across
the cwa. Highs will be in the 70s throughout the period and nudge up
to the 80 degree mark over the southwestern cwa Tuesday and Wednesday.
Saturday will probably be dry. However, a short wave moving across
the region may give us some showers and perhaps a storm Saturday
night.
Sunday looks dry, then another stronger wave arrives Monday night.
Strong low pressure over the northern plains is progd to push a warm
front north into the cwa late Monday night. We`ll likely see showers
and storms develop along/ahead of the warm front with more
development ahead of the trailing occluded front Tuesday.
Showers are possible again Thursday as the Plains low finally moves
over the state.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 754 PM EDT Thu May 2 2024
A stationary boundary is located off to the south of the TAF sites
this evening situated along the MI/IN line. Showers and a few
thunderstorms have been drifting to the north, over Lower Michigan
with a few embedded thunderstorms. At this point we feel
thunderstorm coverage will be on the low side as instability is
forecast to remain fairly low. The stationary boundary will lift
north tonight though and continue to produce rain showers. A cold
front approaches from the west late tonight and will bring in
lower ceilings. MVFR and IFR ceilings will spread into all of the
TAF sites from west to east from 07z to 14z. It will take a good
portion of Friday to clear these lower clouds out. By 21z on
Friday ceilings should have returned to VFR at the last place to
lift which will be JXN. South winds tonight will shift to the west
and northwest on Friday.
&&
.MARINE...
Issued at 304 PM EDT Thu May 2 2024
With a low level jet track through the zones tonight the winds
will be on the increase. They are currently progged to remain
below criteria for small craft advisory so no headlines will be
issued at this time. Outside of the winds increasing over the
lake, gusty winds will accompany the showers and thunderstorms
that track through Lower MI tonight.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
UPDATE...
DISCUSSION...MJS/04
AVIATION...Duke
MARINE...MJS
Area Forecast Discussion
National Weather Service Gray ME
1057 PM EDT Thu May 2 2024
.SYNOPSIS...
Drier weather returns Friday into Saturday, however the pattern
remains unsettled and humid with increasing clouds and more
showers late in the weekend. The upcoming work week starts on a
drying, clearing, and warming trend.
&&
.NEAR TERM /UNTIL 7 AM FRIDAY MORNING/...
1050 PM Update...Updated the forecast mainly for sky cover for
the next several hours as more clearing is taking place across
eastern and northern zones than previously forecast. In these
clear areas, fog is developing and could be locally dense
overnight.
650 PM Update...Showers continue to exit the forecast area as of
this time and will continue to do so over the next hour or two
allowing for mainly dry weather overnight. However, There will
likely be some fog and drizzle around. Little change to the
going forecast.
Previously...
Mesoscale models suggest low pressure will exit southeast through
southern New Hampshire late this afternoon and this evening. This
will allow for the precipitation to diminish and exit off the
coastline and into the Gulf of Maine. The latest HRRR suggests a
couple thunderstorms will be possible as well in a highly sheared
environment.
The large differences in temperatures from southwest to northeast
across the forecast area will continue early this evening prior to
all areas dropping into the 40s by late tonight. Areas of fog will
develop with the most fog in Maine.
&&
.SHORT TERM /7 AM FRIDAY THROUGH FRIDAY NIGHT/...
More low cloud cover and patchy fog will continue Friday morning
across the region, especially over eastern portions of the
forecast area. A large and persistent area of high pressure will
remain entrenched over eastern Canada allowing for the easterly
flow off the Gulf of Maine. It will continue to be cool with
highs in the 50s along the coast and lower 60s across the
interior.
Profiles suggest plenty of low level moisture will continue into
Friday night. Patchy fog will develop once again with
temperatures dropping into the 40s.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Overview: Mid-level ridging will build over the region Saturday
through Sunday but temperatures will remain on the cool side due
to high pressure located to our east, resulting in onshore
flow. Scattered showers will become increasingly likely by
Sunday afternoon through the night before a cold front crosses
on Monday. Behind this front, westerly winds will allow for
warmer temperatures through Tuesday. A passing weak wave of low
pressure will allow for an increased chance for showers towards
the middle to end of next week.
Impacts: No major weather related impacts expected.
Forecast Details: Mid-level ridging and positive h5 height anomalies
will persist Saturday through Sunday. Despite this, surface high
pressure to our east and associated clockwise flow will result
in onshore winds and a continuation of cool and at times damp
conditions. Saturday should remain dry through the daytime hours
but remain mostly cloudy with highs ranging from the 50s to
middle 60s (coolest along the coast and warmest towards the CT
River Valley). Shower chances will then increase on Saturday
night through much of Sunday night as a warm front lifts
northward. Lows will be primarily into the 40s with highs on
Sunday into the 50s.
A cold front will then cross on Monday, bringing an end to the cool
and cloudy conditions. Cloudy skies during the morning will become
partly cloudy by the afternoon with a drying westerly wind. The
additional sunshine will likely allow highs to reach the 60s to
middle 70s in most locations. Warm and partly cloudy skies look
to continue on Tuesday with highs potentially a few degrees
warmer. Shower chances and cooler temperatures then look like
they may make a return towards the middle to end of next week as
a weak wave of low pressure crosses either over or near New
England.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
Short Term...Areas of IFR and LIFR conditions expected tonight in
fog and lowered ceilings. Conditions slowly improve with fog
gradually lifting on Friday but remain with IFR conditions at most
sites in low ceilings. IFR conditions will persist through Friday
night with some LIFR locations in fog as well.
Long Term...Mainly VFR conditions are likely Saturday through
Sunday morning, although onshore flow may result in some lower
ceilings across coastal TAF sites. Scattered -SHRA along with
lower ceilings may result in additional restrictions areawide
late Sunday through Sunday night before improving back to VFR on
Monday morning as southerly winds become westerly behind a cold
front.
&&
.MARINE...
Short Term...A light northeast flow will continue over the area as a
large ridge of high pressure remains over eastern Canada tonight
through Friday night. A light southerly flow may develop during the
afternoon hours on Friday.
Long Term...Southerly winds will become westerly behind a cold
front on Monday but likely remain below 25 kts. Seas will be
between 1-3 ft, highest outside of the bays.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.
&&
$$
SYNOPSIS...
NEAR TERM...Ekster
SHORT TERM...Cannon
LONG TERM...Tubbs
AVIATION...
MARINE...
Area Forecast Discussion
National Weather Service Morristown TN
836 PM EDT Thu May 2 2024
...New UPDATE...
.UPDATE...
Issued at 825 PM EDT Thu May 2 2024
POPs were nudged up slightly in the southern Valley and southern
Plateau late tonight into the early morning hours. Consshort and
HRRR guidance is somewhat high in that area but CAMs have very
spotty light activity, so I was hesitant to increase POPs much
before sunrise. That was the only minor change to the forecast for
tonight. Thunder potential is fairly low through sunrise but a
few strikes will be possible. Expect increasing clouds overnight.
&&
.SHORT TERM...
(This evening through Friday)
Issued at 306 PM EDT Thu May 2 2024
Key Messages:
1. Increasing chances for rain and storms tonight and into Friday.
2. While severe weather is not expected, a few instances of 1/4"
hail and wind gusts up to 40 mph are possible tomorrow afternoon with
any stronger storms.
Clouds increase tonight as high pressure shifts east due to a
shortwave pushing in from the west. This shortwave will bring
increasing chances of POPs, mainly after midnight. Precip most
likely arrives onto the Cumberland Plateau somewhere around
daybreak, then spreading further east into the east TN Valley
through mid to late morning. From late morning into early
afternoon we should see enough instability develop to produce a
few scattered thunderstorms. Shear profiles remain very weak so no
threat of severe weather. HREF SBCAPE probabilities of 500 J/kg
or greater is around 50%. This lines up with what the HRRR is
showing for tomorrow afternoon with SBCAPE values ranging from 300
to 800 J/kg. 0-6km shear will generally be around 20kts, so
perhaps just enough to produce some 1/4" sized hail with any
stronger updrafts. Along with wind gusts up to 40 mph. Again,
just garden variety thunderstorms. High temps will be a touch
cooler tomorrow with the scattered showers and cloud cover around
with highs in the upper 70s to low 80s.
&&
.LONG TERM...
(Friday night through next Thursday)
Issued at 306 PM EDT Thu May 2 2024
Key Messages:
1. Near normal to above normal temperatures through the long term.
2. Unsettled pattern with chances for showers and thunderstorms each
day of the long term. More diurnal pattern of convection last three
days of the period Tuesday through Thursday next week.
Discussion:
Showers and a few storms will likely be ongoing at the start of the
long term period as another shortwave rolls in from the west. By
Saturday morning, the shortwave should be somewhere between western
and middle TN. This wave will nearly be cutoff from the upper level
flow and be a slow mover. Meaning, shower and storm chances remain
on the high side through the day. While showers and a few storms
will be in place Saturday morning, it looks like the highest chances
occur Saturday afternoon. This is due to increasing instability and
the shortwave pushing further east into our area. As with Friday, any
stronger storms will have the ability to produce small hail and
gusty winds but no severe threats are anticipated at this time due
to weak shear.
On Sunday, this shortwave will still be impacting the area as it
won`t completely lift off to our northeast until Sunday evening.
This means another day of scattered showers and storms, though less
coverage compared to Saturday. No severe threats, just garden
variety storms.
On Monday, yet another shortwave rolls through. You guessed it, more
chances for showers and storms. Tuesday through Thursday, a broad
and deep upper trough sets up across the western and central U.S.
With high pressure to our south, this puts our region in quasi-
zonal, southwesterly, flow pattern. During this time, shower and
storm chances will be more diurnally driven. Also, stronger upper
level winds are progged to move in from the west with the approach
of the trough, which means higher shear. This will set the stage
for an increase in severe weather chances. We remain too far out
for much detail other than to keep an eye on the forecast in the
coming days to see how next weeks` pattern evolves.
&&
.AVIATION...
(00Z TAFS)
Issued at 718 PM EDT Thu May 2 2024
VFR conditions will prevail this TAF cycle. High clouds will move
into the region this evening, lowering by morning (still VFR).
Isolated to scattered rain showers will begin near CHA and TYS in
the morning hours becoming more scattered or numerous by
afternoon. Thunder potential will be low in the morning,
increasing in the afternoon hours but even then thunder may be
more isolated. Kept PROB30 chance until confidence increases, a
TEMPO may be more appropriate in later TAF issuances.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 66 81 64 81 / 40 60 60 80
Knoxville McGhee Tyson Airport, TN 62 81 64 78 / 10 70 60 90
Oak Ridge, TN 62 81 63 78 / 10 70 60 80
Tri Cities Airport, TN 58 82 61 75 / 0 40 50 90
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SHORT TERM...
AVIATION...McD
Area Forecast Discussion
National Weather Service Shreveport LA
1048 PM CDT Thu May 2 2024
...New UPDATE...
.UPDATE...
Issued at 1024 PM CDT Thu May 2 2024
A moist and somewhat unstable environment remains in place across
the Four State Region. This can make for challenging forecast, as
any remnant boundary, remnant MCV/MCS, or weak disturbance could
ignite convection across the region. For this update, decided to
lean heavy on HRRR for modifications, as it has done a decent job
with current convection across the Southern Plains. Not expecting
much in the way of precip in the area for a large portion of
evening into the overnight hours. However, decided to keep 20 POPs
over the area, as an isolated shower or thunderstorm can`t be
ruled out in this type of environment. The last several runs of
the HRRR have been very consistent with developing and MCS across
Eastern Oklahoma overnight, and shifting it southward into our
zones north of I-30 after 3am or so. Because of this, decided to
increase POPs between 1am and daybreak for the aforementioned area
to chance and high chance, with high chance across SE Oklahoma
and adjacent SW Arkansas. Otherwise, the remainder of the forecast
remains on track, with overnight lows in the mid to upper 60s.
/20/
&&
.SHORT TERM...
(This evening through Friday Night)
Issued at 313 PM CDT Thu May 2 2024
A few scattered showers will continue to move northeast across
portions of Northern/Northeast Louisiana and Southwest Arkansas
through early this evening in the wake of the departing shortwave
trough that brought this morning`s MCS to the area. Additional
scattered convection may develop this evening along and north of
Interstate 20 along a remnant outflow boundary from the
aforementioned convective complex. The forecast becomes
increasingly uncertain during the overnight hours. For the last
couple of days, model guidance has generally been in decent
agreement that another convective complex will form across Texas
and Southern Oklahoma before diving east-southeast and into our
CWA early Friday morning, in a very similar situation to what we
had today.
The latest models introduce considerable uncertainty regarding
rain chances for Friday. The 12z NAM continues to be far more
aggressive than the remainder of the guidance. The GFS and ECMWF
also depict convection moving east-southeast into the area but
have trended downward regarding coverage, intensity, and QPF
amounts. Meanwhile, the vast majority of the CAMs depict very
little in the way of thunderstorms. Some of them either keep the
next MCS to our west and southwest, or don`t even show one
developing. The NSSL-WRF is the most supportive of another
convective complex, but has it quickly weakening with eastward
extent into the ArkLaTex by 09z-12z. Most of the guidance tends to
struggle in this type of pattern with a persistent southwest flow
and a surface boundary well to our northwest. The trends in the
CAMs are likely due to today`s convection overturning the
environment and lack of recovery of diurnal instability. However,
with low-level southerly flow and warm air advection some surface-
based CAPE could still recover tonight. If a convective complex
does develop to our west, the key factor in its survival into our
CWA will likely center around something that can help propagate
the complex eastward like a mature cold pool or the development of
a MCV. Unfortunately, as mentioned, model guidance struggles
greatly in these scenarios.
Based on the trends in the models, rain chances were lowered
somewhat after midnight tonight through much of Friday. This also
lowers forecast QPF amounts a great deal, as most locations are
generally expected to see an inch or less of additional rainfall
through Friday evening. Since the heavy rain threat has already
diminished for today, the Flood Watch was cancelled early. The
surface front that the next round of thunderstorms is expected to
develop along should stall near or north of I-30 Friday morning
before lifting back northward during the day. As a result, PoPs
should diminish Friday afternoon and become increasingly confined
to areas north of I-20 before falling below mentionable levels in
most areas by midnight Saturday morning.
CN
&&
.LONG TERM...
(Saturday through next Wednesday)
Issued at 313 PM CDT Thu May 2 2024
Saturday is likely to be a very similar situation to today and
Friday. Another weak disturbance in the southwesterly flow aloft
will trigger thunderstorms along the frontal boundary across the
Plains well to our north late Friday. What`s left of this complex
is expected to move into our area during the day Friday.
Redevelopment along a residual outflow boundary Saturday afternoon
should bring scattered showers and thunderstorms to much of the
northwest half of the CWA. The front should sag farther south
Saturday with yet another round of strong convection developing
along the front and dryline over Texas and Oklahoma. This batch of
storms should initiate farther south and should have a better
chance of reach our CWA during the day Sunday. In addition, the
shortwave trough moving across the Southern Plains appears to be
more defined than previous days, which should result in increase
lift helping to sustain the showers and thunderstorms. Thus,
widespread high PoPs in the forecast for Sunday, especially in the
morning.
Daily chances for showers and thunderstorms in the forecast
through at least Monday and Tuesday. The biggest change early next
week is that a much stronger longwave trough is forecast to lift
from the Southern/Central Rockies and into the Northern Plains.
This should keep the best large scale forcing well to our north
Monday and Tuesday. However, with strong low-level southerly flow
and southwesterly flow aloft, there will be plenty of instability
to fuel more convective development especially as a front finally
begins to move into and across the area on Thursday.
Rain chances are currently expected to be lower than in the short-
term forecast period and more scattered in nature. Combined with
strong southerly winds and warm air advection, perhaps the bigger
story will be the building heat and humidity next week. Daytime
high temperatures should be warming into the 90s in several
locations by Tuesday and may be into the mid 90s in many locations
by Wednesday and Thursday. Very humid conditions are also
expected. This will likely push peak heat index values near or
over the century mark across much of the area south of I-20.
CN
&&
.AVIATION...
(00Z TAFS)
Issued at 632 PM CDT Thu May 2 2024
A very complicated TAF forecast is anticipated over the next
24-hours, as uncertainties remain regarding overnight
precipitation. In the event a line of thunderstorms moves into the
region, TSRA will likely become much more widespread in FM groups.
Regardless, look for IFR and LIFR VIS and CIGS as low clouds
return by 03/10z, with SHRA/-RA following shortly thereafter.
/44/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 69 81 68 86 / 20 50 20 40
MLU 69 81 65 86 / 20 60 30 30
DEQ 65 81 64 82 / 50 40 20 50
TXK 66 81 66 83 / 40 50 30 50
ELD 66 80 63 84 / 20 60 30 30
TYR 70 82 68 84 / 20 40 20 40
GGG 69 81 67 84 / 20 50 20 40
LFK 70 81 68 84 / 20 60 10 30
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
SHORT TERM...09
LONG TERM....09
AVIATION...44
Area Forecast Discussion
National Weather Service San Angelo TX
634 PM CDT Thu May 2 2024
...New AVIATION...
.SHORT TERM...
(This evening through Friday)
Issued at 217 PM CDT Thu May 2 2024
...Severe weather possible today and tomorrow...
A surface low is currently located just to our northwest, with a dry
line across out western most counties and a cold front moving in
from the north. Storms are expected to form later this afternoon and
evening near the low, where the dry line and front interact. Most
models have storms developing in the Big Country starting around 4
this afternoon and continuing overnight. We are seeing some cumulus
development in Nolan County, which could be a precursor for
thunderstorms in the next couple of hours. The majority of models
show most of the activity staying in the Big Country, Heartland, and
northern Concho Valley, with a few storms finding their way into the
our southern counties. Instability will be very high this afternoon
(4000+ J/Kg possible) and wind shear values will be sufficient for
severe development. With the instability as high as it is, storms
could very quickly become severe once they develop and outflow
boundary`s could trigger new storms. The main threat today will be
large hail (2+ inches), but damaging winds and an isolated tornado
are also possible. Localized flooding will also be possible with
these storms, as rain amounts could exceed 2 inches under isolated
storms.
Tomorrow will be slightly cooler for the Big Country, as the cold
front keeps winds from the north and east for the start of Friday.
Winds will return back to the southeast for much of the area and the
dry line will retreat westward again, leaving us with dewpoints in
the 60s and 70s. CAPE values could be in excess of 3000 J/Kg by the
late afternoon. Weak convergence on any residual boundaries and an
upper level disturbance aloft could be enough to produce storms in
the late afternoon. CAMs are differing on coverage for tomorrow. The
HRRR is bringing much more widespread activity, with storms
developing to the west and moving into the area. With the large
instability and sufficient shear, any storm that develops could
produce very large hail, strong winds, and possibly a tornado.
&&
.LONG TERM...
(Friday night through next Thursday)
Issued at 300 PM CDT Thu May 2 2024
Thunderstorm chances will persist across the area into the upcoming
weekend. On Saturday, a cold front will push south into north Texas
during the afternoon hours and then sag south into portions of
the Big Country Saturday evening. Also, a dryline will be situated
across west Texas. Thunderstorms are expected to develop along
the cold front and dryline by late afternoon and early evening, as
large scale ascent increases due to an embedded shortwave in
southwest flow aloft. The airmass within the warm sector will be
moist and unstable, with PW (precipitable water) values between
1.5 and 1.75 inches and CAPE`s around 3000 J/kg. Showers and
thunderstorms should become quite numerous across the area
Saturday evening into the overnight hours, as a strong easterly
low level jet develops. Heavy rainfall is possible, along with
a threat for severe storms capable of producing large hail and
damaging winds. At this time, the greatest threat for severe
storms and heavy rainfall will be from the Concho Valley and
Heartland north into the Big Country. With southwest flow aloft
continuing on Sunday, there will be a continued chance for showers
and thunderstorms across the area. Given adequate shear and
instability, additonal severe storms are possible.
A large upper trough is expected to move north of our area on
Monday, with the dryline mixing east into eastern portions of the
forecast area by late afternoon. Thunderstorms may develop along
and east of the dryline over far eastern sections Monday
afternoon but the better chances will stay north and east of the
area. Looking for a dry forecast Tuesday through Thursday, along
with above normal temperatures through the period, with
temperatures pushing well into the 90s.
&&
.AVIATION...
(00Z TAFS)
Issued at 617 PM CDT Thu May 2 2024
Severe storms with large hail have developed north of Abilene,
and eventually may move southeast toward the city as a cold front
moves through this evening. Otherwise MVFR to IFR stratus returns
overnight, rising to VFR midday Friday,
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 63 82 64 81 / 40 40 40 70
San Angelo 64 90 64 87 / 10 40 30 60
Junction 67 90 66 89 / 20 30 20 40
Brownwood 63 83 66 81 / 50 30 40 60
Sweetwater 62 84 63 80 / 20 40 40 80
Ozona 66 89 64 84 / 10 40 30 40
Brady 64 84 66 83 / 30 30 30 50
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...AP
LONG TERM....24
AVIATION...04
Area Forecast Discussion
National Weather Service Topeka KS
626 PM CDT Thu May 2 2024
.KEY MESSAGES...
- A brief period of dry weather for Friday is expected before a
front brings thunderstorm chances back Friday night and
Saturday AM. These could be strong to severe with small hail
and damaging winds being the main concerns.
- A few systems move across the Plains this weekend, continuing
chances for rain and thunderstorms, mainly south of I-70.
- Large trough moves in Monday and Tuesday bringing another
chance for strong to severe storms across the area.
&&
.DISCUSSION...
Issued at 247 PM CDT Thu May 2 2024
This morning and early afternoon has seen a frontal boundary move
across the area, giving way to scattered showers and thunderstorms.
This boundary is currently situated just southeast of our area and
continuing its way southeast. Over the past hour, scattered elevated
thunderstorms have developed in southeastern KS on the northern
periphery of a MCV that is moving across northeastern Oklahoma. With
pockets of solar insolation ahead of the frontal boundary, MUCAPE
has been able to build to around 1000 J/kg (via SPC mesoanalysist)
with RAP 0-6 km shear approaching 30-35kts. With the enhanced shear
from the MCV and increasing marginal levels of buoyancy, cannot rule
a strong updraft yielding some pea to nickel-sized hail this
afternoon for areas south of I-35. Instability should quickly push
east as the frontal boundary continues east, so do not expect a
prolonged period of storms in this area.
Precipitation chances for far eastern Kansas fizzle out by this
evening at the latest with surface ridging building into the area. A
much anticipated dry and sunny day comes Friday with temperatures
warming into the mid-70s by the afternoon. These conditions will not
last long as a shortwave pushing across the north Plains slides a
frontal boundary through Kansas Friday evening and overnight into
Saturday morning. A brief window of moisture advection should take
place across central Kansas as the low-level ridge axis moves east
of the area Friday morning. This should be enough to increase
instabilities ahead of the boundary to the 1000-1500 J/kg range.
With deep shear maximized closer to the upper-level jet in Nebraska,
north-central and far northeastern Kansas seem like the areas where
shear and instability align for strong to severe storms along the
front to become possible. Steep lapse rates could also help to make
up for the lack of instability helping to pose a threat for damaging
winds and quarter-sized hail. As the boundary moves further into
eastern Kansas, shear should decrease as the main upper low pushes
into the Great Lakes region. This will likely weaken convection as
cool-pool circulation becomes unbalanced. Residual precipitation
behind the system will move out by Saturday afternoon, ushering in
another brief dry period into Sunday morning.
A shortwave moving in from southwestern TX ejects into Oklahoma and
southern Kansas Sunday afternoon that increases rain and elevated
thunderstorm chances into Sunday evening. The main QPF axis stays
closer to the surface low that deepens across central Oklahoma, but
moisture advection north of the warm front in northern OK and
southern KS could bring rain and storm chances into areas south of I-
70 (40-60%). Guidance keeps better instability and shear south of
our area so not expecting too much in the way of severe weather with
this wave.
The next widespread chance for strong to severe thunderstorms ushers
in with a long wave trough axis digging out of the 4-corners region
Monday into Tuesday AM. A large warm sector will develop across much
of the central Plains with the set-up likely to produce severe
weather across the Plains. There still are some discrepancies with
positioning of the main upper-low and will play a role in
determining where better low-level dynamics set up. Regardless, keep
an eye on the forecast in the coming days as this system appears to
have the ingredients for severe weather to occur across the area
Monday afternoon into Tuesday AM.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 624 PM CDT Thu May 2 2024
VFR conditions have returned with gradual clearing expected this
evening and overnight. Some light radar returns can be seen near
and northeast of Topeka sites, but with no evidence of lightning
nearby and instability moving southeast, have decided to remove
the remaining VCTS and continue to monitor. Otherwise, light
NNE winds tonight eventually turn back to the southeast and
increase above 10 kt Friday afternoon as high clouds move back
in.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Griesemer
AVIATION...Picha