Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/28/22
Area Forecast Discussion
National Weather Service Binghamton NY
921 PM EDT Fri May 27 2022
.SYNOPSIS...
Showers and a few thunderstorms are expected overnight and
Saturday as a low pressure system moves through. This will be
followed by warm and dry conditions to finish out the holiday
weekend.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
915 PM update...
Upper level low spinning over central Ohio will move east
overnight and Saturday morning. Cooling aloft over NY and PA
above moist low-levels will continue to lead to destabilization
as it moves east overnight. This will trigger scattered showers
and an isolated thunderstorms into the overnight. This upper
level low will be absorbed into a trough and exit the region
Saturday morning. Scattered showers and isolated thunderstorms
will continue in the morning and then taper down in the
afternoon as the system departs. No major changes to forecast
except tweaking hourly POPs based on radar.
630 PM Update...
Did a quick tweak to the grids related to POPs and current radar
trends. First wave of showers has largely moved through areas
east of I-81 as next batch of scattered showers and an isolated
storms are moving into the Finger Lakes region. This next batch
of showers and a few storms was forming ahead of the upper level
low over the Ohio Valley. SPC mesoanalysis shows cooling aloft
working into NY and PA this evening which will continue to
support convective development. Used HRRR mainly as a first
guess for hourly POPs and tweaked as necessary based on radar
trends. Not expecting any severe weather with this next batch of
showers as CAPEs are pretty low and the bulk of the highest
shear slides east of the showers.
330 PM Update...
The initial line of showers and thunderstorms have entered the
region and slowly pass through. Some locations are between the
heavier rain showers are only getting light showers. Meanwhile a
heavier band has set up over the western Finger Lakes where
heavy rainfall and reduced visibilities are being observed. As
expected, the worst of the storms have been south of the CWA.
The best instability in the region is in the southern portions
of NEPA, Poconos, and Catskills. If storms can get going, then
gusty winds will be the main hazard. Scattered heavy showers and
gusty winds are possible across the rest of the region this
afternoon.
Behind this initial line of showers, it is fairly quiet. Some
lingering scattered showers may develop behind this line this
evening. Otherwise, on and off showers are expected tonight as an
upper level low approaches the area. Despite the environment
becoming more stable after sunset, there is still a chance for
thunderstorms during the overnight hours. The best instability will
be in the Poconos and Catskills though there is no concern for
anything severe after sunset. Tonight`s temperatures will only fall
into the upper 50s and low 60s.
The upper level low moves through the region on Saturday, bringing
another round of scattered showers. There will also be enough
instability present for some isolated thunderstorms. Both CAPE and
shear will be much lower than today, so there is not a concern for
severe weather. PWATs will be just over an inch, so not expecting
anything too heavy either. Total QPF from this afternoon through
Saturday afternoon is generally less than an inch, though could
be locally higher for areas that observe heavy showers today and
tonight. Cloudy skies, rain showers, and northerly flow will
keep temperatures a little cooler tomorrow, only climbing into
the upper 60s and low 70s. The low will move east of the region
and out to sea Saturday night as a ridge moves into the region.
This will bring dry conditions and clearing skies. The low temps
will be in the 40s and 50s tomorrow.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
245 PM Update...
Still looks like Sunday and Monday will be the choice of the
holiday weekend as high pressure builds in over the
Appalachians. Tuesday temperatures will be seasonal, perhaps a
couple degrees above normal, with light and variable winds and
fairly dry in terms of humidity (dewpoints in the middle 40s to
lower 50s). A warming trend will commence on Monday as high
pressure shifts offshore, and deep southwesterly flow from the
Gulf of Mexico spreads into the Great Lakes. Temperatures Monday
will tick up into the mid- 80s across the Catskills, and lower-
90s working into valley locations across the Finger Lakes and
NE PA, with upper- 80s elsewhere. Dewpoints will begin to
increase into the upper-50s to lower-60s, with some morning
valley fog possible Monday morning, and an even better setup
for Tuesday morning.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
245 PM Update...
For Tuesday, as weak backdoor cold front may try to sneak some
cooler air from New England into the Catskills or Poconos,
taking the edge off the heat, but the real cooler air will stay
east of the Hudson Valley. Elsewhere, temperatures will climb
into the upper-80s and lower-90s across most of the area, with
the warmest readings in the Chemung and middle- Susquehanna
valleys, including around Elmira, and down through to Scranton
and Wilkes-Barre. A spot shower or thunderstorm can`t be
completely ruled out in the afternoon with northwest flow
developing over New England, but the better chance for showers
and thunderstorms will come mid-week as a weak cold front
arrives Wednesday, and stalls out somewhere south of the NY/PA
border. This front will lift north again on Thursday as an upper
low slowly moves into the Ohio Valley. This system will
eventually push through the area late in the week, but we may
stay stuck in moist SW flow for a day or two with a stalled out
cold front and upper low off to our west.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
Scattered showers will continue to affect KRME, KSYR, KITH and
KELM before 06z with IFR and MVFR restrictions for a short time.
Overall conditions in all terminals will be mostly VFR this
evening. Then overnight and early Saturday morning the winds
will shift to the northwest and bring cooler and moist air in
underneath a bit warmer air leading to IFR ceilings from around
08z-16z or so most NY terminals except KAVP where ceilings drop
to MVFR overnight for a time. All terminals improve to VFR by
Saturday afternoon. Confidence is fairly high that ceilings will
drop to IFR or very low MVFR all terminals by Saturday morning.
South winds under 10 knots will shift to the west-
northwest by Saturday morning and become slightly stronger with
gusts up to 15 kt at NY terminals. Winds will be lighter at
KAVP.
Outlook...
Saturday night through Tuesday...Mainly VFR, other than
possible valley fog forming at KELM in the pre-dawn hours.
Wednesday...Rain showers/thunderstorms and associated
restrictions are possible at all terminals. Otherwise, mainly
VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...BTL/DJN
NEAR TERM...BTL/DJN
SHORT TERM...MPH
LONG TERM...MPH
AVIATION...DJN
Area Forecast Discussion
National Weather Service Boston/Norton MA
1042 PM EDT Fri May 27 2022
.SYNOPSIS...
Unsettled weather returns tonight into Saturday with scattered
showers and a few thunderstorms. Showers and thunderstorms will be
more widespread Saturday afternoon in the interior where a few
strong to severe storms are possible. Turning warmer and dry with
summer-like temperatures for the rest of the Memorial Day holiday
weekend. Cooling trend Tuesday near the coast and for the rest of
the region on Wednesday as a backdoor cold front moves through.
Somewhat unsettled weather for the end of the week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Showers were moving into portions of RI and southeast MA late
this evening. The last few runs of the HRRR, as well as its
time-lagged ensemble, had the best handle on this. So, this
became the basis for this evening`s update.
Expecting the greatest rainfall chances across RI and southeast
MA through daybreak. Keeping an eye on an area of showers and
thunderstorms moving NE from Maryland. This area may reach CT
and western MA by daybreak, but is more likely to be around for
tomorrow morning.
Minor tweaks to temperatures to reflect observed trends.
745 pm update...
made adjustments to the hourly PoP/Wx grids based on current
radar trends and latest HRRR guidance. As typical, even the
convective allowing models are not lining up perfectly with
reality. For example we had a few showers develop south of RI
and cross Martha`s Vineyard and the Cape that wasn`t modeled to
occur until after midnight. With only meager instability aloft,
the convection should be rather tame for the next few hours. As
previous forecaster mentioned, the increasing low level jet
later tonight could result in a little more robust convection,
but still nothing severe. High dewpoint air will result in
widespread low clouds, with some locally dense fog close to the
south coast/Cape and Islands. Given the strengthening low level
jet, this will promote just enough mixing into the near surface
levels that dense fog should not be expanding much inland.
Previous discussion...
Convective line moving to mid Atlc coast this afternoon where
best instability with showers and isolated thunder further north
across New York. CAMs show sct showers moving into western
MA/CT this evening and can`t rule out an isolated t-storm here
with weakening instability which becomes elevated. Then more
convection is expected to develop overnight as forcing increases
with the approach of the amplified mid level trough. Most of
the HREF members focus showers and isolated t-storms from
eastern CT through RI and eastern MA. This is along the axis of
a modest low level jet and slightly more elevated CAPE. Locally
heavy downpours are possible with any heavier showers/t-storms
as PWATs spike to 1.50-1.75+ ahead of the cold front.
Stratus will become widespread tonight as it advects northward from
the Islands. Fog, locally dense will be mainly confined near the
south coast. It will be a mild and humid night with lows in the
60s.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
Saturday...
De-amplifying mid level trough sweeps across SNE during the
afternoon. While it is weakening modest cooling aloft combined with
surface heating will help to generate modest instability with CAPES
up to 1000 J/Kg in the interior. There will be lots of stratus in
the morning along with showers and isolated t-storms exiting the
Cape/Islands leading to a dry period. In addition, cross sections
show moisture decreasing enough for some breaks of sun in the
afternoon away from the coast which will aid with destabilization.
Increasing forcing from right entrance of upper level jet and low
level convergence with the cold front should allow numerous showers
and sct t-storms to develop in the afternoon. 0-6km shear is
decreasing and best shear is ahead of the developing storms but
there is an axis of shear values up to 30-35 kt coincident with the
developing storms in the interior. Cooling temps aloft will help to
produce mid level lapse rates near 6 C/km which is neutral. Low
level lapse rates are not great but if we can generate up to 1000
J/kg of CAPE, a few strong to marginally severe storms will be
possible, mainly NW of I-95 corridor. Max updraft potential from
HREF indicate main timeframe of severe potential from noon to 6 pm
in the interior. Expect showers and storms to weaken as they move
into RI and SE MA late in the day and evening as instability wanes.
Highs will be mainly in the low/mid 70s, cooler immediate south
coast, but some upper 70s to near 80 possible across NE MA.
Saturday night...
Lingering showers and isolated storms exit SE MA in the evening,
then expect improving conditions behind the cold front as drier air
moves in. Clearing skies and light N/NW winds will allow temps to
drop into the 50s with readings close to 50 across NW MA.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
12z model suite not offering too much in the way of significant
changes from what we had in the forecast, though the
probability of seeing a backdoor front situation developing
Tuesday is much higher, and thus making for a very tricky
temperature forecast for Tuesday and Wednesday. Overall quiet
weather Sunday through Tuesday with building warmth as mid/upper
level ridging becomes firmly established to our west along
roughly 80W longitude. Steering flow starts off westerly, but as
the ridge extends north, we get into a northwest flow regime.
The pattern looks to me like a "ring of fire" situation, where
upper level disturbances in the atmosphere will zip around the
periphery of the ridge and trigger rounds of convection. However
southern New England appears to be too close to the ridge and
under the influence of strong subsidence at least through mid-
week to have to worry about that. Convection should come no
closer than northern New England. As mentioned above, confidence
is higher that a back door cold front will ooze southwestward
from coastal Maine on Tuesday and make the temperature forecast
tricky. Global models all suggest the strong ridge will start to
break down and be pushed southward for the second half of the
week. This should result in higher chances for unsettled weather
to develop. Overall kept close to the NBM for the forecast. A
few notes regarding each day follows....
Sunday: Pretty good day for outdoor activities. Rather dry airmass
behind Saturday`s system. 850mb temperatures will be in the 9-11C
range, which supports surface temperatures about 24-26C (77-80F).
Boundary layer flow will be out of the west, but not very strong, so
sea breezes will develop, keeping immediate coastal locations in the
lower 70s for highs.
Memorial Day: In response to the building ridge, 850mb temperatures
will be in the 16-18C range, supporting high temperatures of 31-33C
(88-92F). NBM v4.1 guidance shows a decent signal for 90+ highs in
parts of the region, specifically a 50-60% chance of above 90F in
the CT River Valley and 35-45% chance in the Boston Metro Area.
Dewpoints will be higher than on Sunday, somewhere in the upper 50s
to about 60F. Not enough to feel the humidity, but enough to
generate decent surface instability. We should see CAPE values of
400-700 J/kg across western half of the area and even a decent EML
with about 7.5C/km lapse rates between 700-500mb. Normally I`d be
concerned with severe weather, however as mentioned earlier, we will
have a strong inversion in place between 6000-8000ft above the
ground which will cap any attempt of convection.
Tuesday: Synoptically, it appears very similar to Monday. 850mb
temperatures quite similar. Northwest flow, strong subsidence
inversion etc. Would suggest hot again for the region. Not so
fast. With the mid/upper level ridge pattern even more
amplified, this will allow low level cooler air across Maine and
the Canadian Maritimes to be dislodged and push south/southwest
as a backdoor cold front. Timing is uncertain, but it does
appear by mid-day that cooler air will be moving onshore. The
question will be exactly how far west does that cooler air push.
NBM probabilities of 90F+ show 60-70% across the CT, while it`s
0-5% along the east coast/Cape and Islands. ORH to PVD has a
roughly 20-30% chance of reaching 90F per the NBM. Wherever that
backdoor cold front sets up, there will likely be a 20-25F
degree gradient over 20 miles or less. I know I`m not that good
to pinpoint exact locations hour by hour this far out, so all I
can say is that the western quarter of the forecast area has
high confidence of seeing 90F. The eastern quarter of the
forecast area has high confidence of seeing below normal
temperatures. Everywhere else in between, please use the
temperature forecast with extreme caution. Did keep with some
low PoPs along the back door front as a few showers or even an
isolated storm can`t be ruled out, but we will still have the
inversion aloft, so those PoPs are only 15-20%.
Wednesday-Friday: Ridge starts breaking down, allowing mid/upper
level disturbances to potentially come across the area. Would think
the backdoor front will be in place for most of Wednesday (warmer
west, cooler east), but with models showing weak low pressure moving
through and flow turning more westerly, that should start to push
that cooler air east during the day. Subsidence inversion aloft also
weakens, so we should have enough instability and lifting to
generate scattered showers and t-storms. Stuck with NBM for
temperatures and PoPs each of the days given the increasing
uncertainty. As the ridge weakens, we get into the path of those
"ring of fire" disturbances that are next to impossible to time with
any real accuracy this far out. With the NBM offering "typical
summer" weather with highs in 70s/low 80s and daily PoPs in the 30-
40% range, I saw no reason to vary from that.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Overall moderate confidence.
IFR conditions are developing across most of the region, with
LIFR across parts of the Cape, Islands and immediate south
coastal areas. Have some light to briefly moderate showers
moving across the area currently. Model guidance suggests the
development of additional scattered showers after 04z,
especially for RI into SE MA. Given some model struggles the
last few hours, scattered showers may end up being almost
everywhere, though more concentrated in the SE. Have a lot of
VCSH in the TAFs, with predominate -SHRA for sites like PVD,
FMH, HYA and ACK. Strengthening winds above the surface will
also result in LLWS across the SE portion of the area.
Saturday...
IFR/LIFR in the morning with scattered showers exiting
Cape/Islands. Improving to MVFR/VFR in the afternoon but IFR
persisting over Cape/Islands. Scattered to numerous showers and
t-storms will be developing across the interior in the
afternoon with a few strong storms possible with convection
weakening as it moves to the coast late in the day. Uncertainty
in exact timing and placement at this point means I only kept
the mention to VCTS. SW wind gusts to 20 kt.
Saturday night...
Conditions improving to VFR as winds shift to NW. IFR cigs and
patchy fog may linger over Cape/Islands before improving to VFR
after midnight.
KBOS TAF...Moderate confidence in TAF. Ceilings are expected to
lower below 010 in the 03-05z timeframe. Maybe some -SHRA
overnight, but just not enough certainty to pinpoint timing
beyond just VCSH. Guidance suggests that surface visibilities
will only fall into the MVFR category. Forecast issues for
tomorrow afternoon revolve around the time ceilings will lift
and development of nearby TSRA. What is in the TAF is only a
best estimate at this point.
KBDL TAF...Moderate confidence in TAF. Timing of ceiling changes
are only best estimates. Forecast issues for tomorrow afternoon
revolve around the time ceilings will lift and development of
nearby TSRA.
Outlook /Sunday through Wednesday/...
Sunday through Sunday Night: VFR.
Memorial Day through Monday Night: VFR. Breezy.
Tuesday through Tuesday Night: VFR.
Wednesday: Slight chance SHRA, isolated TSRA.
&&
.MARINE...
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Today into Tonight...High confidence.
Modest low level jet over the waters. This will lead to 20-25 kt
gusts today and 25-30 kt gusts tonight. Seas building to 5-6 ft
across the open waters late today and tonight. Stratus and fog
lingers with visibilities of 1/2 to 3 NM. Could see some
showers/storms tonight as a warm front lifts through. SCA
remains in effect.
Saturday...High confidence.
Modest low level jet still in place, but moves offshore late in
the day as a cold front slides in. Winds out of the S/SSW with
gusts of 25-30 kt to start diminishing to 20-25 kt late in the
day. Low clouds along with fog linger until the front passes
through. Could perhaps see a few showers/storms with the front
moving in. Visibilities of 1/2 to 3 NM. Seas 4-6 ft across the
open waters.
Outlook /Sunday through Wednesday/...
Sunday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Sunday Night through Memorial Day: Winds less than 25 kt. Seas
locally approaching 5 ft.
Monday Night through Tuesday: Winds less than 25 kt. Areas of
seas approaching 5 ft.
Tuesday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Slight chance of rain showers.
Wednesday: Winds less than 25 kt. Seas locally approaching
5 ft.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 5 PM EDT Saturday for ANZ232.
Small Craft Advisory until 2 PM EDT Saturday for ANZ231-233-
234.
Small Craft Advisory until 2 AM EDT Saturday for ANZ230-251.
Small Craft Advisory until 11 PM EDT Saturday for ANZ235-237.
Small Craft Advisory until 8 PM EDT Saturday for ANZ250.
Small Craft Advisory until 8 AM EDT Sunday for ANZ254>256.
&&
$$
SYNOPSIS...KJC/Nash
NEAR TERM...Belk/KJC/Nash
SHORT TERM...KJC
LONG TERM...Nash
AVIATION...Belk/KJC/Nash
MARINE...KJC/Nash
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
918 PM CDT Fri May 27 2022
.UPDATE...
Issued at 918 PM CDT Fri May 27 2022
Going forecast generally in good shape this evening, with clearing
skies from the north and diminishing winds as surface high pressure
ridge develops into the area. Only significant change was to hit fog
potential harder later tonight across IL portion of the forecast
area south of I-80. Not out of the question that a dense fog
advisory may be needed late tonight/early Saturday morning across
some portion of that area.
Evening surface analysis indicates low pressure and surface cold
front continue to move away to the east/southeast of the forecast
area. Breezy north winds have pulled drier air into the region from
the north, allowing for a steady erosion of cloud cover from north
to south across the forecast area since late afternoon. Weak surface
high pressure ridge was drifting into northern/central IL beneath
subsidence/rising heights in the wake of the departing upper low.
This was allowing surface winds to quickly diminish and become light
and variable. The combination of wet ground conditions from recent
rains, late day or evening clearing and light winds overnight will
likely allow for fog development across parts of the forecast area.
Locations most likely to see more widespread and possibly dense fog
looks to be south and southwest of Chicago, where later clearing and
smaller temp-dewpoint depressions will likely be most conducive for
fog. Various model visibility guidance (HRRR, GLAMP, etc.) highlight
this area for more widespread lower visibilities as well. Have thus
hit fog harder in our gridded and text forecasts for these areas
overnight, and can`t rule out the need for a dense fog advisory
heading into the pre-dawn hours of Saturday morning. Other locations
will likely see some patchy shallow ground/radiation fog develop as
well.
Otherwise, going forecast appears to be in good shape heading into
Saturday. Winds will become southerly as the surface high pressure
ridge slips east of the area in the morning. Only potential blip is
the chance of some low-coverage spotty showers thunderstorms mainly
across far northern IL (mainly north of I-88 or I-90) in the
afternoon/early evening hours. Forecast soundings depict dry
profiles below about 10 kft, though some moistening within a layer
of steep (7.5 C/km) lapse rates above that along the southern
periphery of a mid-level short wave tracking across the upper
Midwest/northern Lakes could support some isolated to widely
scattered high-based convective showers. 00Z 3 km WRF and HRRR runs
continue to suggest this possibility, though with a fairly small
footprint with better chances north of the forecast area. Current
slight chance pops into Saturday evening appear reasonable for
now.
Ratzer
&&
.SHORT TERM...
Issued at 318 PM CDT Fri May 27 2022
Through Saturday night...
A few lingering showers will remain possible through early evening
as the upper low moves eastward into the Mid-Atlantic region. A
ridge will build into the area this evening which will work to clear
out the cloud cover and lighten the winds to around 5 mph this
evening. As the skies clear, the light winds and leftover moisture
will create favorable conditions for fog to develop across much of
the western portions of the CWA. Guidance is rather spotty in
coverage of the fog, but given the aforementioned conditions I opted
to include a mention of patchy fog in the forecast for much of
northeastern Illinois during the predawn hours Saturday morning. Any
fog that does develop should quickly burn off after sunrise with
mostly clear skies dominating the rest of our Saturday.
As the ridge settles in southerly flow will develop and bring warmer
air into the region and keep us primarily dry. However, a weak upper-
level disturbance does look to move along the outer edge of the
ridge which may allow for some showers to develop Saturday
afternoon. Forecast soundings do show a lot of dry air throughout
the atmosphere which should keep this chance to a minimum, but since
there is a bit of uncertainty in the exact position of the
disturbance I did maintain a slight chance mention for showers
across far northeastern Illinois and along the lakeshore.
Regardless, temperatures on Saturday will climb into the mid to
upper 70s across much of the area with cooler temperatures in the
60s along the lakeshore. Winds will also be increasing in speed
during the day on Saturday as the atmosphere should be able to mix
into 20 kt winds aloft which will create periodic gusts in the mid
to upper teen range during the afternoon.
Yack
&&
.LONG TERM...
Issued at 330 PM CDT Fri May 27 2022
Sunday through Friday...
A warm, mostly dry, and breezy second half of Memorial Day
weekend is in store.
Windy and warmer conditions are expected Sunday as an upper ridge
builds into the Great Lakes region over stout low-level WAA. Low-
level winds will quickly increase through the day between broad
low pressure over the northern High Plains and high pressure along
the mid-Atlantic seaboard. A strong inversion will remain present
through the day under a deep EML advecting into the region,
keeping mixing heights quite low for late May. While increasing
mid/upper clouds associated with a subtle wave riding along the
western flank of the ridge will subdue some mixing across at least
the northwest half of the CWA in the afternoon, mixing should
sufficiently tap into 35-40kt winds along the inversion. Southerly
winds will likely gust to 35 mph through the afternoon, with
sporadic 40+ mph gusts not out of the question.
While the lowest 10 kft of the atmosphere will be exceptionally
dry, a layer of moisture in the 12-15kft layer will align with the
wave noted above and may tap into steep 8.5C/km 400-600 hPa lapse
rates. This supports the possibly of highly elevated convection
across at least the northwest half of the CWA in the afternoon and
early evening. While precip will have a hard time overcoming the
dry air below 12kft, the combination of the very dry air and
existing strong low-level winds may result in widely isolated
gusty sprinkles/light showers under any stronger elevated cells.
Sub-850 hPa mixing heights on Monday under the existing deep EML
will allow for rapidly warming conditions during the morning
hours. Coming off morning lows in the upper 60s to perhaps low 70s
in the Chicago metro combined with 925 hPa temps of 23-25C and
mostly sunny skies will yield afternoon temps around 90F for much
of the area. Temps will have a chance to over-perform into the low
90s if better low-level moisture advection remains confined to
areas west of the CWA and dew points mix out into the upper 50s.
Climatologically speaking, temps of at least 90F on Memorial Day
occur less than 10% of the time, with the Monday`s record high of
93F in Chicago not totally out of reach.
Another warm day is expected on Tuesday, but a western CONUS
trough will begin to erode the western edge of the ridge by this
time. the forecast across the CWA will depend heavily on the
evolution of an associated cold front currently progged to drift
southeast into the area Tuesday night. As the EML erodes and
advects eastward on Tuesday, convective inhibition may diminish
enough to allow for isolated storms ahead of the cold
front/trough. Modest mid-level lapse rates and deep layer shear
will present a non-zero severe storm risk Tuesday afternoon and
early evening.
Forecast guidance is in general agreement that the cold front
will stall somewhere across Illinois Tuesday night into Wednesday
ahead of another mid-level Wednesday night into Thursday,
resulting in the potential for an axis of heavy rain near and
north of where the front stalls.
Kluber
&&
.AVIATION...
For the 00Z TAFs...
Aviation forecast concerns for this TAF period include:
* Potential for patchy fog at RFD, DPA, and GYY early Saturday
morning
* Low chance for an isolated shower or storm near the terminals
during the late afternoon or early evening on Saturday
Overall, a quieter period is in store for the next 24-30 hours
relative to the past 2 days. MVFR ceilings are clearing early this
evening, and once the remaining stratocumulus departs to the south
or diminishes, only some passing isolated to scattered higher
cloud cover is expected through the remainder of the TAF period.
The clearing skies and light winds tonight, in conjunction with
the presence of leftover moisture from recent rainfall, will aid
in the formation of fog across parts of northern Illinois and
northwest Indiana. This is mainly expected to occur towards
central Illinois where the influence of a surface ridge axis will
be greatest tonight, but could foresee at least patchy fog
occurring anywhere outside of the heart of the Chicago metro. Have
opted to keep the inherited TEMPO groups for reduced visibility at
RFD, DPA, and GYY with medium confidence that visibilities could
dip down to at least MVFR there for a few hour long period prior
to daybreak.
Winds will turn southerly by late Saturday morning with sustained
winds expected to generally hover at or just above 10 kts during
the afternoon and evening. There could be some sporadic southerly
gusts that approach 20 kts towards the end of the TAF period, but
have decided against adding an explicit mention of this for the
time being.
Only other thing worth mentioning at this time is that there is a
low (roughly 20%) chance of isolated to widely scattered showers
passing near or over the terminals during the late afternoon and
early evening on Saturday as a mid-level disturbance passes by to
our north. Most guidance favors this shower activity remaining
north of the terminals, but if the disturbance takes a more
southerly track like some models are advertising, then at least a
VCSH mention may eventually need to be added to the TAFs. However,
considering that the preponderance of forecast guidance keeps us
dry tomorrow and that dry sub-cloud air could make it difficult
for any hydrometeors to reach the ground if these showers do end
up far enough south, felt that the introduction of a PROB30 for
this activity was not warranted at this time. There will be some
meager instability aloft for any cells to work with, which could
also allow for the possibility of an isolated thunderstorm or two
to pass near the terminals if there`s just enough moisture to work
with in the low-mid levels. Forecast trends will need to be
watched closely for this reason, but based on current guidance,
think that seeing any storms, let alone showers, near the
terminals tomorrow is rather unlikely.
Ogorek
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement...ILZ006-ILZ103-ILZ104 until 10 PM
Friday.
IN...Beach Hazards Statement...INZ001-INZ002 until 4 AM Saturday.
LM...Small Craft Advisory...IL nearshore waters until 10 PM Friday.
Small Craft Advisory...IN nearshore waters until 4 AM Saturday.
&&
$$
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Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1011 PM EDT Fri May 27 2022
.SYNOPSIS...
A cold front will move through the area Saturday morning. High
pressure builds back into the region early next week.
&&
.NEAR TERM /THROUGH SATURDAY/...
As of 1010 PM Fri...Skies beginning to clear somewhat across the
coastal plain while convection begins to build over the Gulf
Stream. Still a chance of thunderstorms developing across the
sounds overnight as surface front nears and upper low continues
to pivot slowly eastward; several of the previous HRRR and
experimental WoF runs support this idea. If they develop,
environment would be marginally supportive for stronger storms
capable mainly of damaging winds and perhaps a very brief
tornado with localized low-level convergence zones. Updates to
previous forecast are tracking well and made only minor
adjustments.
Prev disc...Latest analysis shows an anomalously deep upper low
spinning over the upper Mid-West with attendant cold front
moving towards the Appalachians. Deep southerly flow continues
from the Gulf of Mexico north through the SE US. Within this
southerly flow, an anomalous plume of moisture is overspreading
the entire US East Coast, characterized by a large area of
1.5"-2" PWat values. Latest mesoanalysis shows SB CAPE values
1000-2000 J/kg with 30-40 kt of bulk shear. Radar shows
convection waning along the coast early this afternoon, with
convection now re- developing across central NC and SC near area
of enhanced instability. Latest HRRR keeps this activity just
west of the coastal plain through this evening, but could impact
western portions of the area. Stronger mid-upper jet max will
overspread the area this afternoon and eve as the cold front
continues to slowly advance east through the Carolinas. This
will lead to increasing deep layer shear and slightly more
curved hodographs. At the same time, though, instability may
tend to be on the downward trend due to the loss of daytime
heating and the worked over atms. High shear/low CAPE scenario
will likely set up as the cold front progresses east into, and
through, ENC during the evening and overnight hours, mainly with
a damaging wind and brief tornado threat. There is still the
threat of severe weather this evening and into the overnight,
but confidence remains low at this time. Showers and
thunderstorms will likely be slowly progressing through the area
late tonight, and may begin clearing the area from west to east
after midnight. However, with the upper trough axis remaining
back to the west through the night, will keep pops in through
the overnight, tapering off from west to east late. Guidance
(HRRR and HREF) continues to show convection blossoming along
the coast late tonight, after 06z. So an isolated svr threat may
continue along the coast late.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH 6 PM SATURDAY/...
As of 3 PM Friday...Sfc cold front associated with a cut off
low lifting into the Mid-Atlantic will continue to push offshore
Saturday morning with a few lingering showers and perhaps a
tstorm possible along the coast. Cut off upper low will continue
to weaken as it lifts into the NE US while trough becomes more
positively tilted. Isolated showers and tstms may develop along
the seabreeze, which will likely be pinned along the coast with
low level westerly flow inland. Modest instability along the
coast, enhanced convergence and weak upper forcing may be
enough to support isolated convection, which should wane with
loss of daytime heating. Low level thickness values support
highs in the 80s.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
As of 330 AM Fri...High pressure builds in for the latter half
of Memorial Day Weekend.
Sun through Thu...Drier conditions expected Sun with high
pressure and upper level ridging beginning to build into the
region. A stacked high will linger across much of the Eastern US
to start off the week, bringing mostly dry conditions through
Wednesday. Aftn temps will begin to push into the low to mid
90s, creating a short stretch of hot weather. The next frontal
boundary will approach the region Thu night.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /through Saturday/...
As of 755 PM Fri...Currently VFR conditions across the terminals
with only very light shower activity approaching OAJ from the
southwest. VFR conditions are expected to prevail through the
evening with little to no precip activity through 04z, but
convective activity will likely blossom for terminals mainly
east of a line from OCW to EWN after 04-05z. EWN may be
initially impacted by this activity for a couple hours before
bulk of activity moves eastward overnight. Some sct MVFR cigs
are probable as the front sags south.
VFR conditions prevail Sat with low clouds scattering out and
westerly winds for most of the day. This will keep sea breeze
pinned closer to the coast, which will trigger showers and a few
storms. Sites most vulnerable are OAJ/EWN.
LONG TERM /Saturday night through Wednesday/...
As of 345 AM Fri...Prevailing VFR conditions expected
through Tuesday as high pressure builds overhead.
&&
.MARINE...
SHORT TERM /through Saturday/...
As of 245 PM Friday...Latest obs show S winds 15-25 kt with
seas 4-6 ft. Gusty southerly winds 15-25 kt will continue
through tonight ahead of an approaching cold front. Seas will
peak at 4-7 ft, highest across the central and southern waters.
SCA continues for the sounds and coastal waters. The cold front
will move through the waters Saturday morning, with flow
becoming more WSW early. Conditions will quickly improve through
the day Sat with winds 5-15 kt and seas subsiding to 3-5 ft by
mid morning/early afternoon. Scattered showers and
thunderstorms continue along the coast early this afternoon, and
may increase in coverage late tonight and early Sat am just
ahead of the front. Strong wind gusts, small hail, dangerous
lightning, and waterspouts will all be possible with the
thunderstorm activity (especially tonight).
LONG TERM /Saturday night through Wednesday/...
As of 350 AM Fri...High pressure builds in Sunday through
Tuesday to bring a nice stretch of favorable boating conditions
with variable winds around 10-15 kts and seas 2-3 ft.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Beach Hazards Statement from 8 AM EDT Saturday through
Saturday evening for NCZ196-204.
MARINE...Small Craft Advisory until 7 AM EDT Saturday for AMZ135-150.
Small Craft Advisory until 2 AM EDT Saturday for AMZ131-230-
231.
Small Craft Advisory until 1 PM EDT Saturday for AMZ152-154.
Small Craft Advisory until 11 AM EDT Saturday for AMZ156-158.
&&
$$
SYNOPSIS...MHX
NEAR TERM...CQD/MS
SHORT TERM...CQD
LONG TERM...ML
AVIATION...MS/ML
MARINE...CQD/ML
Area Forecast Discussion
National Weather Service San Francisco Bay Area
445 PM PDT Fri May 27 2022
.SYNOPSIS...Far inland areas will continue to cool today and
Saturday, otherwise, not much change from present weather
conditions through the Memorial Weekend. The one notable exception
is the possibility of sprinkles or light rain in the North Bay
Saturday afternoon and potentially into the Bay Area itself
Saturday evening, as the tail end of a weak cold front passes
through. A brief warming trend is then expected next Tuesday and
Wednesday followed by a cooling back to seasonal values.
&&
.DISCUSSION...as of 01:06 PM PDT Friday...Satellite imagery this
afternoon still showing stratus over much of Sonoma County, over SF
Metro, along the coast, and surrounding the entire Monterey Bay. The
stratus is slowly burning off, but do not expect a huge warm up for
places that have been stuck under the stratus into this afternoon.
Have gently lowered temperatures for the Santa Rosa region and for
sites around Monterey Bay due to the stratus impact.
The upper level trough impacting the Pac NW and NorCal will dominate
our weather through the holiday weekend, including Monday. That
means we`ll stay in a cooler, onshore flow regime with clouds along
coastal regions at night and morning. With that trough will come a
surface cold front with the weaker, tail end of it swinging into
NorCal on Saturday. The latest rain arrival based on our Hi-res
models:
Updated HRRR timing shows a 3pm arrival for NW Sonoma County then
spreading Southward with the potential for light rain/sprinkles
tracking far enough south to hit the SF Metro/Peninsula area in the
5-8p window.
NAM timing shows arrival into NW Sonoma County closer to 4pm then
tracking southward with light rain/sprinkles potentially hitting SF
Metro/Peninsula in the 7p to midnight window.
Rain amounts, in places that do get rain, remain light with our hi-
res models and the ECMWF ensemble members...from sprinkles to a few
hundredths around the SF Bay Area northward. This weak cold front
passage will not be super impactful other than bringing a welcomed
spritz of moisture and the need for occasional windshield wipers
while driving.
After the Holiday Weekend, we`re expecting a Tuesday-Wednesday warm
up as an upper level ridge develops over the Eastern Pacific and
then moves inland. The WPC 3-7 day cluster analysis shows that the
ridge looks well organized when it`s still offshore. However, as it
moves inland on Wednesday, the clusters don`t have solid agreement
in its strength or location. Thus, we don`t have confidence that
this warm up will be notable like we had earlier this week. The NBM
continues to show that highs will peak in the mid 80s to low 90s
across the interior in that Tue-Wed timeframe...not the upper 90s to
low 100s we just experienced.
Moving into the extended forecast, we see an interesting return to a
cooler pattern as another upper level low moves into the Pac NW and
NorCal. Our interest is piqued because both the GFS and ECMWF
ensemble members are hinting at another light rain event around the
first weekend of June. We`ll be monitoring this to see if the trend
remains, especially since some of the forecast rain amounts are
around a tenth of an inch in the North Bay.
&&
.AVIATION...as of 4:44 PM PDT Friday...For the 00Z TAFs. Low
clouds continue to affect coastal areas and is starting to filter
into the SF Bay. VFR is expected to last the more inland
terminals, but MVFR is expected around the Monterey Bay and the SF
Bay as well as the North Bay into the night. The lowered CIGs
will be begin to thin in the mid to late morning, with VFR
expected for Saturday.
Vicinity of KSFO...VFR into the night followed by MVFR. Westerly
winds will stay moderate through the night. Stratus will filter into
the SF Bay through the evening and fill into night, causing MVFR.
Expect VFR to return in the mid morning around the SF Bay. Westerly
winds become breezy Saturday afternoon and look to last through the
early night.
KSFO Bridge Approach...Similar to SFO.
Monterey Bay...Becoming MVFR into the evening and lasting through
the night. Expect light winds overnight. VFR returns with some
breezy westerly winds Saturday afternoon.
&&
.MARINE...as of 04:44 PM PDT Friday...Increasing northwest winds
this afternoon and evening. Locally strong winds will develop
through the Golden Gate, south of Pigeon Point and along the Big
Sur coast. These winds will be hazardous to small craft vessels.
Expect more active marine conditions late this weekend into early
next week with increasingly hazardous winds and seas developing.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tngt...SCA...SF Bay until 9 PM
SCA...Pigeon Pt to Pt Pinos 0-10 nm until 9 PM
SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm from 6 PM
&&
$$
PUBLIC FORECAST: Bingaman
AVIATION: Murdock
MARINE: SPM
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Area Forecast Discussion
National Weather Service Spokane WA
515 PM PDT Fri May 27 2022
.SYNOPSIS...
The Memorial Day weekend will be showery, cooler than average,
and some spots over extreme eastern Washington to the southern
Panhandle may struggle to reach 50 degrees Sunday with a steady
cool rain. A warming and drying trend is expected next week.
&&
.DISCUSSION...
The forecast for the remainder of the evening has been updated to
limit the chance for thunderstorms to north of the metro area. RAP
instability analysis depicts a bit of weak surface based CAPE
lingering over Pend Oreille, Bonner, and Boundary counties where
observed dewpoints remain in the mid 40s to near 50. There may
also be additional thunderstorm development south of Grangeville
this evening along the trailing end of a cold front. Elsewhere,
light rain showers will move across portions of the Palouse into
the central Idaho Panhandle through the evening. /GKoch
&&
.AVIATION...
00Z TAFS: A mid level wave that has brought showers with embedded
thunderstorms this afternoon will continue to push east this
evening with drier and more stable conditions developing from west
to east. Thunderstorms threat should be east of KPUW/KLWS by 00z
but some shower activity may linger until 02-03z. A moist boundary
Some drying in the boundary layer over Central WA combined with
west winds should keep most of Central and Eastern WA with VFR
CIGS through Saturday afternoon. Current models show the drying
may not push far into North Idaho as boundary layer winds shift to
the south by late evening, with a good chance for stratus by
Saturday morning including KCOE.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 44 59 45 62 46 65 / 10 10 10 20 30 30
Coeur d`Alene 45 58 44 61 45 64 / 10 10 10 30 30 30
Pullman 44 57 45 53 42 57 / 50 10 20 50 40 30
Lewiston 50 65 51 60 49 64 / 60 10 40 60 50 30
Colville 41 63 42 68 47 70 / 10 10 10 20 20 30
Sandpoint 45 59 44 63 46 64 / 40 10 10 40 50 40
Kellogg 46 56 44 57 46 61 / 50 20 10 50 60 40
Moses Lake 44 65 47 67 46 69 / 10 10 10 20 10 10
Wenatchee 46 64 50 65 49 68 / 0 20 20 20 10 10
Omak 44 64 48 69 49 71 / 0 10 10 20 20 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$