Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/07/21
Area Forecast Discussion
National Weather Service Bismarck ND
1004 PM CDT Thu May 6 2021
.UPDATE...
Issued at 1000 PM CDT Thu May 6 2021
Main update is to let the Red Flag Warning Expire at 10 PM CDT.
Humidity values are still low across portions of central North
Dakota, although winds are starting to lessen and shift to the
northeast. With clear skies and cooling temperatures, humidity
trends should also improve through tonight. Thus have let the Red
Flag Warning expire. Otherwise forecast remains on track for
tonight. Clear skies are now found throughout the entire CWA. As
mentioned, winds will switch to the east and be light tonight.
Look for low temps in the 20s and 30s. Friday could be another
near critical to critical fire weather day, with chances for rain
moving in on Saturday.
UPDATE Issued at 754 PM CDT Thu May 6 2021
Many areas in the Red Flag Warning are still seeing low RH values
in the teens while north northeast winds remain near to above
critical thresholds of 20 to 25 mph. These critical fire weather
conditions should improve, although are slow to do so. Given the
high fire danger for today and slow to improve conditions, went
ahead and extended the Red Flag Warning until 10 PM CDT. After 10
PM, winds should begin to lessen and become more easterly.
Temperatures will cool with the setting sun and allow for RH
values to improve. A Fire Weather Watch remains for northwestern
portions for Friday afternoon/evening.
UPDATE Issued at 633 PM CDT Thu May 6 2021
Minimal updates needed early this evening. Critical fire weather
conditions continue to be found across central and eastern
portions. Red Flag Warning will continue for these areas until 8
PM CDT tonight. Winds will lessen and become easterly later this
evening, while skies go on a clearing trend. A few isolated
showers may linger across the southeast early this evening before
moving out of the area. A mild and dry day will then be found for
Friday. Breezy east winds in the west will bring near critical for
critical fire danger.
&&
.SHORT TERM...(This afternoon through Friday night)
Issued at 311 PM CDT Thu May 6 2021
Critical fire weather conditions continue this afternoon across
most of central North Dakota with several sites showing humidity
values in the 10 to 20 percent range and sustained winds to 25 mph
out of the northwest. Thus, today`s Red Flag Warning looks to be
in good shape. A few radar echoes have developed along and
behind a southward advancing cold front. However, due to the very
dry airmass/dewpoint spreads/high cloud bases, little if any
precipitation will reach the ground. Still with a couple of ground
truth observations, decided to put mention of light isolated
showers into the forecast generally across the southern half of
the forecast area and east of the Missouri River.
Winds will diminish around and after sunset and humidity values
will recover. Expect overnight lows in the mid 20s to mid 30s.
Attention then turns to the possibility of more critical fire
weather conditions on Friday across the northwest. Flow will turn
southeasterly ahead of an approaching trough. This flow regime
should limit mixing somewhat, but a very dry airmass will still be
in place across the northwest with humidity values dropping to as
low as 17 percent. In this area, winds are also expected to become
breezy, up to 25 mph with gusts to 35 mph. Used a 50/50 blend of
NBM and RAP for dewpoints across the northwest where we should mix
out a bit more. Because of these factors, we went ahead and issued
a Fire Weather Watch for the northwest on Friday. Across the
southwest, we will not be quite as dry but winds will still be 20
mph or greater during the afternoon so near critical fire weather
conditions will certainly be possible here. Winds diminish as you
move east.
An upper level ridge axis starts to break down as it moves
overhead Friday night as a surface low begins to deepen near the
Montana/Wyoming border. Height falls will then lead to increasing
precipitation chances across the west and into portions of the
central overnight.
.LONG TERM...(Saturday through Thursday)
Issued at 311 PM CDT Thu May 6 2021
The trough to our west closes off and the upper low stalls out
across central Montana on Saturday, becoming nearly stacked. A
band of strong frontogenesis will extend from the low northwest
to southeast, bringing widespread precipitation to eastern Montana
and possibly much of the west and portions of the central.
Ensembles continue to shift the axis of heavier precipitation
slightly to the east and north. Confidence is increasing that we
will see some much needed soaking rains at least across the
southwest. There will be a tight gradient where the precipitation
cuts off, which will generally be along a line from around
Williston to Bismarck. Subtle changes in the track of the low
could have significant implications on where this gradient sets
up. To the west and south of the gradient, locations could see
0.50" to 1.00" of rain. To the north and east, locations could
very well see little if anything. 12z GEFS plumes illustrate the
uncertainty in where the gradient sets up nicely. There is quite a
bit of clustering in the plumes at KDIK for Saturday, generally in
the 0.25" to 0.75" range. However, looking at the plumes for KBIS
we see almost zero clustering with still a wide range of
possibilities.
With this system comes much cooler temperatures, with highs on
Saturday ranging from the lower 40s in the southwest, to the mid 50s
in the north central. Chances for rain persist through all of
Saturday and into the day on Sunday, with slightly warmer high
temperatures in the 50s. There doesn`t look to be a strong flow
pattern aloft next week, leading to scattered low precipitation
chances that remain inconsistent between guidance. A relatively
low spread in NBM temperature percentiles confirms a slow but
steady warming trend through midweek, with highs expected to be
back in the widespread 60s by Wednesday and possible some lower
70s by Thursday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 633 PM CDT Thu May 6 2021
VFR conditions and breezy winds at times can be expected through
the forecast period. Clearing skies look to be found through
tonight, with only an isolated shower possible across
southeastern ND this evening. Breezy northerly winds will
diminish late this evening and become easterly. Some breezy east
winds may then be found for Friday, while mainly clear skies bring
VFR conditions to all sites.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Friday afternoon through Friday evening
for NDZ001-002-009-010-017-018.
&&
$$
UPDATE...Anglin
SHORT TERM...ZH
LONG TERM...ZH
AVIATION...Anglin
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
916 PM EDT Thu May 6 2021
.UPDATE...
Issued at 916 PM EDT THU MAY 6 2021
Only some higher-based showers have made it into our area, as
lightning has ceased on the first batch of convection. and There
is another broken line of storms working into western Tennessee,
but these will stay well west of our generally weaken with time.
The latest RAP soundings look even more meager on the instability
overnight now, and given the tamer trends upstream, have decided
to remove thunder for the rest of the night. While a stray flash
can not be completely ruled out, the overall probability just
looks too low to maintain at this point. Better PoPs also will be
more confined to the northern and northeastern portion of our
area, with less coverage in the south and southwest. As such,
have made some adjustments, accounting for the latest mosaic
radar trends upstream, as well as more recent higher resolution
model guidance. Forecast lows look reasonable for most locations;
however, will have to adjust a few of the more sheltered valleys
a bit lower in the east, as partial clearing and low level dry
air has allowed for a quick drop off this evening. Dew points are
still several degrees lower, so another few degree drop off is
achievable in the next hour or so, before thicker clouds keep the
cooling in check. Updates will be forthcoming.
UPDATE Issued at 632 PM EDT THU MAY 6 2021
A convective line, initiating out ahead of an approaching cold
front currently aligned across western Kentucky, is weakening
rapidly as it heads east into south central Kentucky. The latest
SPC Meso Analysis indicates little to no instability just west of
our area, and the latest RAP forecast for even small amounts of
ML CAPE advecting into our area does not look promising through
this evening. As such, will keep out the mention of thunder with
this initial weakening line as it approaches our doorstep between
8 and 9 pm. As the heart of the vorticity lobe and its associated
cold temperatures aloft approach later tonight, a few storms can
not be completely ruled out, and will maintain these slight
chances for that time. The rest of the forecast remains on track
and will only freshen up the hourly temperatures and sky cover,
incorporating the latest trends in the observations and satellite
imagery. Updates will be out shortly.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 440 PM EDT THU MAY 6 2021
A shortwave trough extending from the upper Great Lakes to the mid
Mississippi Valley this afternoon is rotating around a larger
synoptic scale trough over the eastern part of the continent. It
is supporting a weak surface low with a cold front extending
southwestward. Thunderstorms are occurring along and ahead of
the front this afternoon, with one line over western KY. The
convection will advance east with the system tonight, and is
expected to bring precip to the JKL forecast area. Low level
moisture will be minimal and instability will be weak, but with
thunder ongoing and at least some instability shown by models for
our area, a slight chance of thunder was maintained.
This system departs to the east overnight and early Friday, with
brief surface ridging translating east through the region during
the day Friday bringing fair wx for most of the day.
Another shortwave trough swings southeast from the Great Lakes on
Friday to the central Appalachians by Saturday morning. It will
support another cold front which will drop in from the north late
Friday and pass on Friday night. Once again, there will probably
be at least some showers with the system. Despite a lack of
significant low level moisture, very cold air aloft will still
mean a risk of some thunder. This activity should be finished by
Saturday morning as the front drops to our south and the shortwave
departs to the east.
.LONG TERM...(Saturday through Thursday)
Issued at 510 PM EDT THU MAY 6 2021
The extended period begins Saturday with eastern Kentucky under
continued northwesterly flow just to the west of the axis of a more
broad upper level trough. Further into the weekend, a wave of energy
coming off a larger low out in the western CONUS moves into the Ohio
Valley Sunday. The next feature of interest is a trough that moves
east across the CONUS early next week, reaching our region by
Wednesday or so, though timing specifics are still yet to be worked
out. At the surface, a developing surface low over the Rockies will
move east over Saturday, with an associated warm front stretching
east towards the Tennessee Valley. As this low nears the Ohio Valley
late Saturday into Sunday it pushes this warm front north through
our area. The low continues east Monday and drags a cold front
through the day Monday, with high pressure trying to nudge in behind
it. Wednesday into Thursday, another developing area of low pressure
to our south looks to potentially impact our area. However there is
not good agreement over the timing of this low, or the upper level
wave supporting it.
Rain chances will be on the increase Saturday with the approach of
the warm front, especially Saturday night. Going into Sunday, the
GFS does have the system, and its associated warm front, pushing a
little farther north than others, bringing the better precip chances
north of the area for a time. However, the ECMWF had more ensemble
support in its position of the low further south. So, kept the PoPs
more in line with its solution, leaving precip chances across the
area with the best chances in the northern portion of the area.
Thunderstorms are also possible Sunday afternoon into Sunday night.
Rain continues Monday with the front moving through the area, before
it finally pushes out Monday night. Tuesday and Tuesday night, the
NBM still had chance to slight chance PoPs in the area, especially
in our south. However, given the high pressure trying to work in,
and the persistence of the dryer solutions within models, kept more
consistent with the previous forecast and left PoPs out for a large
part of that time frame. The location and movement of the next
system is still varying a good bit between models, so stayed with
the NBM for Wednesday and Thursday, but kept the chances restricted
to chance due to the uncertainty. This has rain chances returning
Wednesday, with thunderstorms possible in the afternoon and early
evening. Rain chances continue through Thursday with more
thunderstorms possible in the afternoon.
Temperatures still have room for further refinement near the
beginning of the extended since there is still a little bit of
uncertainty around the front`s progression. At this point though,
highs saturday are cooler, only a few degrees on either side of 60.
Sunday looks to be a little bit warmer with most places climbing
into the 70s. Highs through the rest of the period stay mild in the
low to mid 60s. Lows generally stay in the 40s through the period,
outside of Sunday night where some areas may reach the low 50s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
ISSUED AT 734 PM EDT THU MAY 6 2021
A passing upper level disturbance and surface cold front will
bring lowering ceilings and shower activity to the area this
evening and into the overnight. The initial line of activity will
weaken as it affects KSME between 00 and 01z, and then KLOZ
between 01 and 02z. Conditions are expected to remain VFR;
however, some west northwest winds could get gusty briefly at KSME
at the onset of the rain showers. Precipitation chances will fill
in across the rest of the area later tonight, with ceilings
dropping down to MVFR between 06 and 12z. The cold front and upper
level support will exit by early Friday morning, with a return to
VFR conditions from west to east, as lower clouds break up. Light
and variable winds through this evening will become west to west
northwest at around 5 kts behind the cold front. West to
northwest winds will then increase to 5 to 10 kts, with gusts of
15 to 20 kts by late Friday morning.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...HAL
LONG TERM...HAS
AVIATION...GEOGERIAN
Area Forecast Discussion
National Weather Service Miami FL
807 PM EDT Thu May 6 2021
.AVIATION(00Z TAFS)...
Scattered/Numerous TSRA ongoing near all east coast terminals. Threat
may linger through 01-03Z before progressing offshore into the
Atlantic waters. Brief IFR/LIFR conditions may be experienced
near any storm, with VIS reductions, low CIGs, strong/severe wind
gusts, and small hail all possible. A cold front will progress
southerly towards the area overnight, allowing for winds to shift
clockwise from SW to N/NE by tomorrow afternoon. Convective threat
becomes more isolated and less potent for tomorrow afternoon.
&&
.UPDATE...
Scattered/numerous thunderstorms encompass portions of the east
coast metro regions, with a few storms already producing severe
wind gusts and 0.5 in hail. Considering slow storm motion and
efficient moisture transport, localized flooding becomes a concern
in urban and poorly drained areas. The stronger storms will
progress eastward into the Atlantic waters with time, and overall
storm coverage should wane by around 9-10pm tonight, though
isolated showers and storms may linger. An approaching cold front
will allow for winds to turn clockwise, becoming N/NE by tomorrow
afternoon. This will allow for slightly lower temperatures, though
still warm. Additionally, only isolated/scattered showers and
thunderstorms are possible with the less favorable air-mass.
&&
.PREV DISCUSSION... (Issued Issued by National Weather Service Tampa Bay Ruskin FL)
SHORT TERM (Rest of Today through Friday)...
19Z water vapor and H4 RAP analysis showing a highly amplified
upper level pattern has evolved over the CONUS...featuring sharp
ridging over the inter- mountain west and downstream troughing to
the east of the MS Valley. Florida finds itself within the base
of this trough...with an embedded shortwave passing by this
evening. This shortwave energy will help to propel a late season
cold front down out of central Florida into our region overnight
and Friday morning before stalling over the Florida Straits.
The atmosphere remains quite unstable this afternoon across south
Florida in the pre-frontal environment. Visible satellite imagery
shows well defined east and west coast seabreeze boundaries well
established, and both starting to kick off the anticipated storms.
Over the next few hours we should see the west coast boundary
evolve eastward and eventually interact with the eastern sea-
breeze along/near the I-95 corridor. With this forecast philosophy
in mind...storms should also consolidate with time toward the
eastern Metro area. This evolution is in fairly good agreement
among the model consensus and forecast storm evolution follows
the 12Z HREF fairly close. I-95 corridor counties remained
outlooked in a marginal risk for severe weather through this
evening by the storm prediction center...in agreement with where
the most robust surface convergence is likely to occur in the
hours to come.
Storm will evolve offshore into the Atlantic and/or dissipate
within a few hours of sunset...leaving the region to see a mostly
dry frontal passage late tonight.
This "cold front" will really be primarily responsible for
bringing some drier air to the region the next 48-60 hours. This
time of year it is difficult to really cool things off much, and
temperatures will again be up near 90 for most locations on
Friday. Some leftover residual moisture over coastal Dade/Broward
counties and enhanced convergence of the stalled frontal boundary
and sea-breeze may be enough to support a few late day storms,
although coverage and updraft intensity potential looks less than
today.
LONG TERM (Saturday through Next Thursday)...
The upper level pattern flattens out quickly as we head into the
weekend and the eastern trough ejects over the north Atlantic.
Surface high pressure will exist from the eastern Atlantic to the
Florida peninsula and eastern Gulf of Mexico under this zonal flow
aloft...keeping our weather seasonable and mainly dry.
Much of the early and middle portion of next week look warm and
seasonably humid. Any significant shortwave energy in the synoptic
westerlies looks to stay generally north of the region, however,
slight enhancements in lift may promote an afternoon or evening
through Wednesday. At this point, none of this activity looks
organized or widespread.
Still a ways out, but some indications of another more significant
amplification to the longwave pattern late in the week over the
eastern conus that could result in another late season front and
more organized thunderstorm activity by Thursday or Friday. Still
plenty of time to watch the pattern evolve and adjust the
forecast.
AVIATION(18Z TAFS)...
The first round of convection has developed around PBI with an
additional round expected this afternoon/evening around the east
coast terminals. IFR/LIFR impacts with strong wind gusts and hail
cannot be ruled out at terminals that are directly impacted though
confidence is not high enough to restrict with short-fused AMDs
likely. Convection should diminish after sunset into the
overnight with light wind returning. Sea breeze formation is
expected again on Friday with convection possible again later.
MARINE...
Southerly winds shift northwest late tonight and Friday morning
before local sea-breezes again shift winds onshore near the coast
in the afternoon. A northeast wind flow develops for Saturday and
then easterly by Sunday as high pressure builds north of the
region. The early portion of next week will feature mainly
southeasterly winds as the high pressure area slides eastward
into the Atlantic. Winds may approach cautionary levels at times
Sunday into early next week.
&&
.PRELIMINARY POINT TEMPS/POPS...
Miami 74 90 72 86 / 60 40 10 10
West Kendall 72 91 69 88 / 60 30 10 10
Opa-Locka 73 90 70 86 / 60 40 10 10
Homestead 72 89 70 85 / 60 30 10 10
Fort Lauderdale 74 89 72 85 / 60 40 10 10
N Ft Lauderdale 74 88 71 83 / 60 30 10 10
Pembroke Pines 73 90 70 85 / 60 40 10 10
West Palm Beach 71 86 69 83 / 60 20 10 0
Boca Raton 72 88 71 84 / 60 20 10 10
Naples 74 87 65 89 / 10 10 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
GM...None.
&&
$$
Update/Aviation...Bhatti
Visit us at weather.gov/miami
Follow us on Facebook and Twitter at:
www.facebook.com/nwsmiami
www.twitter.com/nwsmiami
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1028 PM EDT Thu May 6 2021
.SYNOPSIS...
Weak low pressure will develop along a front stalled to our
south tonight and Friday. The low will lift northeast offshore
late Friday. High pressure will build across this weekend with
another frontal system expected early next week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 10 PM Thu...A few isolated showers persist along a quasi-
stationary 850 mb moisture boundary over southeast NC late this
evening. Expect this activity to wane through the rest of the
evening, though a couple of showers through the early morning
hours mainly along the coast south of Cape Hatteras can`t be
ruled out. Otherwise, stratus clouds persist, especially south
of US Hwy 264, with lows mainly several degrees below normal.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
As of 250 PM Thursday...Confidence is increasing for some much
needed rain, especially over the southern coastal zones for
Friday. As surface low pivots northeast just offshore along
stalled frontal boundary, most all of the high-resolution
models including the 3km NAM, NSSL WRF and HRRR are showing
widespread convective showers along with some isolated
thunderstorms. Steep lapse rates coupled with 25-30 knots of
effective shear could lead to some strong to marginally severe
storms with brief wind gusts and hail being the primary threats.
The Storm Prediction Center has placed a portion of our CWA in a
Marginal (level 1/5) threat for severe weather tomorrow. The
high-res models show convective rain elements that could
produce some needed downpours for the area, especially the
southern zones and QPF totals of upwards of one-half inch are
forecast. Have increased PoPs to likely for most of the area
Friday, especially from midday into late afternoon. High
temperatures will be in the upper 60s north to low/mid 70s
elsewhere tomorrow.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
As of 305 AM Thu...The weekend appears dry before the next
frontal system impacts the area Monday through the rest of the
period.
Friday night...Clearing skies overnight and CAA behind the
departing low point to abnormally cool lows in the mid 40s.
Saturday and Sunday...High pressure builds in from the southwest
for the weekend ushering in dry and moderating conditions.
Temperatures climb into the low to mid 70s Saturday, followed by
upper 70s to low 80s by Sunday with increasing southwesterly
flow. With approach of next front late Sunday winds will
increase overnight Sunday with breezy conditions forecast for
OBX.
Monday through Wednesday...Guidance in reasonable agreement next
front will approach the Carolinas Monday morning and cross the
CWA late in the day, bringing an increased chance of showers and
storms. Hesitant to introduce likely PoPs at this point as
frontal passage timing has varied a bit from run to run. For
now, will keep high-end chance mention. Front stalls over the
Gulf States Tue-Wed with weak high pressure attempting to build
in from the north before another wave of low pressure develops
along the boundary midweek bringing a renewed chance for
precipitation.
Highs Monday will be the highest of the long term reaching into
the mid 80s, before falling back into the low 70s for the
remainder of the week with lows in the 50s.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /Through Friday/...
As of 8 PM Thu...Low level moisture boundary remains draped
across the region, with mostly cloudy to overcast skies across
most of eastern NC. A few showers will continue into the
overnight hours, but the probability of them having any
significant impact at a terminal is low. Overall VFR prevails
overnight with light winds. Shower activity will increase
Friday, with rain likely at all terminals in the afternoon,
potentially bringing sub-VFR conditions. Thunder is also
possible with a few storms maybe becoming strong enough to bring
gusty/erratic winds. Ceilings will be low end VFR, but could
occasionally dip to high end MVFR.
LONG TERM /Fri Night through Tuesday/...
As of 305 AM Thu...High pressure builds back Friday night and
into the weekend and early next week with VFR conditions
returning.
&&
.MARINE...
SHORT TERM /Tonight and Friday/...
As of 10 PM Thursday...Light to moderate NW flow persists across
the waters, with weak troughing along the coast and ridging
inland. Over the waters south of Cape Lookout, winds will veer
to more SW by morning in response to surface low to our south
moving offshore. All winds speeds Friday will be 5-15 knots with
seas 2-4 feet.
LONG TERM /Fri Night through Tuesday/...
As of 315 AM Thu...Coastal low developing off the coast Friday
will lifting north of the area Friday night. The Euro is a
happy medium between all guidance and leaned the forecast
heavily in its direction. This results in a forecast for SCA to
develop and spread across all waters by Saturday morning with
winds 20-25 kt. The window will be small and expect seas to
build to predominantly 3-5 feet, although a few 6 footers are
possible well offshore.
High pressure builds south of the waters later Saturday and
Sunday with improving conditions, with next potential concern
being late Sunday and Monday as southwesterly winds increase
ahead of an approaching cold front. Winds increase to 20-25 kt
for coastal waters and Pamlico Sound, aiding in seas surging to
a peak of 6-8 feet.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...MHX
NEAR TERM...CTC/CB
SHORT TERM...CTC
LONG TERM...MS
AVIATION...CTC/CB/MS
MARINE...CTC/CB/MS
Area Forecast Discussion
National Weather Service Marquette MI
758 PM EDT Thu May 6 2021
.SHORT TERM...(This evening through Friday)
Issued at 414 PM EDT THU MAY 6 2021
WV imagery and RAP analysis indicated a mid/upper level low over
James Bay with a broad trough through the Great Lakes into the
southeast CONUS. a weak shortwave trough combined with daytime
heating and low level convergence near Lake michigan has supported
some light shower or sprinkles over southeast Upper Michigan. A more
vigorous compact shrtwv located over northwest Ontario, north of
KINL, was not producing much more that sct light rain showers into
northern MN so far.
Tonight, as the upstream shrtwv approaches, expect sct showers to
increase into the west this evening. There is more uncertainty with
the pcpn trends overnight. The NAM along with several high res
models and SREF plume members suggest that a band of heavier pcpn,
exceeding 0.5 inch QPF, could develop over north central Upper
Michigan. Expect enough dynamic and evaporative cooling to change
the rain over to snow in the higher terrain where the pcpn is
heaviest. With steep mid level lapse rates to 8C/Km and strong
forcing with the shrtwv, this may not be unreasonable. However,
confidence in the development and location of any higher QPF is low
given the amount of spread, so only included QPF in the 0.10-0.25
inch range with snowfall amounts into the 1 to 2 inch range over the
north central. An SPS was issued to highlight the potential for some
hazardous driving conditions with slushy roads.
Friday, the shrtwv and associated pcpn will quickly exit central
Upper Michigan into the east during the morning and during the
afternoon. Northerly winds behind the cold front and 850 mb temps
in the -4C to -6C will result in max readings only from the lower
40s north to the mid and upper 40s south.
.LONG TERM...(Friday night through Thursday)
Issued at 410 PM EDT THU MAY 6 2021
The extended is pretty uneventful for the most part. The U.P. should
be fairly dry and cooler for this weekend and into the early next
week. Temperatures should warm up a bit by the mid week as the dry
conditions continue. There is a slight chance for some showers late
in the extended period, but other than a stray shower or two not
much more precipitation is expected.
As a low remains fixed over northern Ontario for this weekend and
early next week, expect temperatures to remain cooler (ensembles
show 850mb temperatures in the 10th percentile until Monday night).
While this low may bring a few shortwaves over the area, don`t
expect any rainfall to occur, as ensembles show PWATs in the 10th
percentile until mid next week. Therefore, drying is expected over
the area, which could cause some concerns in regards to drought,
particularly in the east where there is a moderate drought occurring
(see CPC homepage). As the temperatures warm over mid next week, the
drying trend is expected to continue, which may be worth noting in
regards to fire weather and drought concerns.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 753 PM EDT THU MAY 6 2021
This evening and tonight, a weak cold front and disturbance will
move through the region from northwest to southeast bringing a
chance of rain showers into the west. Enough cooling is expected
for the precipitation to change to snow at KCMX and KSAW. A period
of IFR conditions is likely at KSAW while mainly MVFR conditions
should prevail at KCMX. A few inches of slushy snow will also be
possible at KSAW. Slowly improving conditions are expected Fri
morning.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 414 PM EDT THU MAY 6 2021
North winds will increase to around 20 knots and back to the
northwest as a cold front moves through the region. The pattern will
then be quiet across Lake Superior into next week. During this time,
winds are expected to be below 20 knots.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...TAP
AVIATION...Voss
MARINE...JLB
Area Forecast Discussion
National Weather Service Nashville TN
623 PM CDT Thu May 6 2021
.UPDATE...
FOR 00Z AVIATION DISCUSSION.
&&
.DISCUSSION...
Convection beginning to take place upstream across the Mo bootheel
northeastward along the Ohio River. Latest Hrrr data has the
activity reaching our far northwestern corner around 3-4 pm. A svr
tstm watch is now in effect to our west. Severe wx parameters do
indeed look better across that area and not as favorable here.
Therefore, it looks as though the severe weather potential in our
western areas will largely be momentum dependent. That said, recent
storm history upstream will be key. So far, no reports of wind or
hail but a few warnings have been issued across the bootheel. For
our area, wind and hail are the primary threats for primarily those
areas west of i-65. The weakening convection will end across our
Plateau by 10pm - midnight.
Moving on, Friday is looking partly cloudy and nice with highs 65 to
70. Conditions will begin to change on Saturday as a warm front
begins to work northward. Low shower chances will return early
Saturday and continue into Saturday night. On Sunday, the warm front
will be north of the mid state and destabilization will be on the
increase. A cold frontal passage is expected Sunday evening. Prior
to this, frontal and pre frontal forcing will attempt to tap into
the instability and increasing shear. Another round of severe storms
will be possible. Note however that at this time we are not
outlooked. That will likely change to at least a marginal as we
approach Sunday.
For our near term temps, below normal values are expected. However,
we will be close to the normal, upper 70s highs, on Sunday, in
advance of that boundary.
In the ext fcst, after the fropa on Sunday evening, temperatures
will cool down to 7-10 degrees below normal for the entire week. The
subtropical jet will become active and send an inverted sfc trough
our way by Wednesday. So the week as a whole will be on the
unsettled side with low shower chances, except somewhat higher
chances for Wednesday.
Qpf amounts are not looking too bad. Looks like 1 to 1 1/2 inches
over the next 7 days.
&&
.AVIATION...
00Z TAF DISCUSSION.
Line of showers and a few thunderstorms are working their way
through the area, currently impacting KBNA/KMQY with near MVFR
cigs and IFR/MVFR vis. Strong northwest winds around 20 to 30
knots will be possible for another half hour to around 00Z, then
expect 5 to 10 knot winds out of the west/northwest overnight.
Showers should impact KCSV from around 01Z through 03Z. Rest of
the overnight will be VFR for all terminals except for KCSV which
may see MVFR cigs from 06Z through sunrise. VFR conditions area
wide during the day Friday with northwesterly winds around 10
knots.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......21
AVIATION........Barnwell