Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/16/19

Area Forecast Discussion

National Weather Service Bismarck ND

 925 PM CDT Sun Sep 15 2019

.UPDATE...
Issued at 924 PM CDT Sun Sep 15 2019

No changes needed for this update. Benign weather continues.

UPDATE Issued at 633 PM CDT Sun Sep 15 2019

The only change for this update was to add patchy fog to the
Souris River Valley late tonight into early Monday morning.
Several consecutive runs of the HRRR have strongly suggested fog
development in this area, and examination of model soundings
confirms that favorable atmospheric conditions for fog do exist.

A weak disturbance currently observed on GOES channel 9 (6.95
micron) water vapor imagery over eastern Montana will pass through
the area this evening into tonight, but is only expected to
produce some mid to high clouds.

&&

.SHORT TERM...(This evening through Monday)
Issued at 229 PM CDT Sun Sep 15 2019

An upper level trough off the southern Canadian west coast this
afternoon is forecast to continue digging and expanding south into
the Pacific Northwest states and California tonight and Monday.
Meanwhile the downstream ridge over the Canadian and US Plains will
continue to build as its apex moves east towards the Great Lakes on
Monday afternoon. This will result in southwest flow aloft over the
Dakotas Monday and Monday night.

At the surface, weak high pressure was over North Dakota this
afternoon as low pressure was developing in the Lee of the Rockies.
Tonight and Monday the Rockies low pressure is forecast to continue
to develop and keep a southerly low level wind flow along the Plains
states and provinces. This will keep warm air with surface dewpoints
in the 50s and 60s across western and central North Dakota. After a
very warm day today in the 80s/90, we can expect overnight lows in
the 50s/lower 60s...and an even warmer day on Monday with highs in
the mid 80s/mid 90s. As mentioned in the previous discussion, the
00z NAEFS 850 mb temperature anomaly percentiles are maxed out
across much of the forecast area on Monday.

.LONG TERM...(Monday night through Sunday)
Issued at 229 PM CDT Sun Sep 15 2019

Well above average temperatures are expected to continue Tuesday,
with chances of thunderstorms returning to the forecast by Tuesday
afternoon. Then more seasonable temperatures by mid-week (highs in
the 70s) with chances of showers and thunderstorms returning Friday
and Saturday.

The aforementioned upper level longwave trough will be well-
established over the west coast Monday afternoon. The base of the
trough is forecast to begin moving eastward across the Rockies
Monday night, then lift northeastward as it begins to deepen and cut
off from the main flow as its own smaller-scale shortwave. This
feature reaches the western Dakotas Tuesday afternoon and moves
northeastward across western North Dakota Tuesday night, and into
southern Manitoba on Wednesday. This scenario will induce a surface
trough in the Lee of the Rockies that will deepen into a more
established low with a more distinct warm front ahead of the system
and its associated low level jet ahead of the system - and a strong
cold front trailing the system as the surface low and associated
cold front move east/northeast across western North Dakota Tuesday
night and Wednesday.

Look for breezy southerly surface winds to bring humid conditions
(dewpoints in the 60s) to western and central North Dakota ahead of
the system Monday night and Tuesday...then gusty/windy westerly
winds Tuesday night and Wednesday as the cold front moves through
the area and the intensifying system results in a tight pressure
gradient across our area. Look for another very warm and humid day
Tuesday with highs in the 80s. As mentioned in the previous forecast
discussion, the 00z NAEFS 850 mb temperature anomalies are in the 99
to 99.5 percentiles across much of the area.

Regarding showers and thunderstorms, chances begin Tuesday evening
in western North Dakota, then spread into north central ND Tuesday
night and Wednesday. The Storm Prediction Center has placed
southwestern North Dakota and much of the south central in a Day 3
Marginal Risk for severe weather (for Tuesday night). Today`s 12z
model runs indicate decent 0-6km shear (35-45 knots) Tuesday
afternoon and night. However, model differences in timing of the
available moisture suggest there could be a brief window Tuesday
evening where CAPE values would support strong to severe
thunderstorms.

After the cold front sweeps through, another western US trough
deepens once more, allowing moisture to again return to the region
by the end of the week. This pattern will bring more chances of
showers and storms across the region Thursday night through Saturday
night. A cool weekend ahead with highs in the 60s and lows in the
40s.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 633 PM CDT Sun Sep 15 2019

VFR conditions are expected through the forecast period, though
fog may develop at KMOT late tonight into early Monday morning.
There may be a few hours of low-level wind shear concerns at KJMS
overnight, with 2-kft winds reaching 40 kts out of the south-
southwest. Expect south to southeast surface winds through the
forecast period, around 5 kts tonight and increasing to 10-15 kts
by Monday afternoon.


&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...Hollan
SHORT TERM...JV
LONG TERM...JV
AVIATION...Hollan



Area Forecast Discussion

National Weather Service Caribou ME

 934 PM EDT Sun Sep 15 2019

.SYNOPSIS...
Low pressure over the northern Maritimes will slowly move east
to the open north Atlantic by Monday night. Canadian high
pressure will then gradually build eastward towards the area
Tuesday, crest over the region Wednesday, and slowly move south
of the region Thursday and Friday.

&&

.NEAR TERM /THROUGH MONDAY/...
933pm Update...Updated PoPs as an area of isolated light
showers has formed Downeast, with light rain in Bangor. HRRR has
this area of showers likely to track along coastal and inland
Downeast through midnight. The associated shortwave now well
visible on satellite, pivoting across southern and central Maine
this evening. Light showers and lower ceilings have also
approached the Crown of Maine, albeit more widespread than
those Downeast.

Prev Discussion...
Mainly Dry and Cool thru this portion of the Forecast

A mid lvl s/wv trof will initially be tracking ewrd across our
FA this eve, which will keep bkn-ovc SC cld cvr along with
isold to sct shwrs for our Rgn. Behind this initial s/wv, skies
will become ptly cloudy N to msly clr Cntrl/Downeast late tngt.
After a start of ptly to msly sunny skies Mon morn, a last
trailing s/wv from Cntrl QB will bring more in the way of SC cld
cvr alg with isold shwrs spcly to Nrn and Cntrl ptns of the FA
before move SE of the FA Mon eve.

Otherwise, cont`d llvl cold advcn with NW winds will keep the
Rgn relatively cool thru Mon. Typical of SC cld cvr and a lgt
breeze across all of the Rgn will not allow much in the way of
radiational cooling ovrngt.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
Surface and upper lows will continue to slowly exit east of the
Canadian Maritimes Monday night, while surface high pressure
remains centered to our northwest. Expect partly to mostly
cloudy skies Monday night with lows generally in the mid to
upper 40s across the region. Tuesday will be a mainly sunny day
with below normal temperatures as surface high continues to
build toward the region. Tuesday night is expected to be a very
cold night for northern areas as the high builds right across
the region. The potential is there for a widespread
freeze/frost for much of the far north. Lows Tuesday night
across the colder northern valleys are expected to fall into the
upper 20s to lower 30s. Will likely need freeze/frost headlines
for Tuesday night for the far north. After a very chilly start
to the day Wednesday, we will see mainly sunny skies along with
afternoon high in the low to mid 60s regionwide.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Another chilly night is expected Wednesday night, otherwise the
late week period is looking to be fair with a warming trend, as
an upper ridge builds toward the region. By Friday highs are
expected to be well above normal for this time of year, with
temperatures climbing into the mid 70s for many areas. The upper
ridge is expected to continue to hold into at least the
beginning of next weekend with above normal temperatures and
continued dry weather expected.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
NEAR TERM: This Eve and Ovrngt: VFR all TAF sites. Breezy W
winds.

Late Tonight through Monday: Nrn TAF sites MVFR SC clgs.
Downeast sites VFR. Lgt winds.

SHORT TERM: Mon Night thru Fri...VFR expected through the
period, outside of any patchy early morning fog Tuesday night
and Wednesday night, mainly KPQI vcnty.

&&

.MARINE...
NEAR TERM: No hdlns anticipated attm thru these ptns of
the fcst, with fcst wv hts based on a blend of WW3/NWPS wv
guidance. Wvs will be comprised of two main spectral groups durg
this tm; a 5-7 sec offshore SE propagating short fetch group
and a NNW propagating 10-12 sec open Atlc swell group.

SHORT TERM: Winds/seas expected to be below SCA levels through mid week.
Long period swell could begin to affect the waters late week.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...None.

&&

$$

Near Term...Cornwell/VJN
Short Term...Duda
Long Term...Duda
Aviation...Cornwell/VJN/Duda
Marine...Cornwell/VJN/Duda



Area Forecast Discussion

National Weather Service Grand Rapids MI

 915 PM EDT Sun Sep 15 2019

LATEST UPDATE...
Update

.SYNOPSIS...
Issued at 300 PM EDT Sun Sep 15 2019

- A few lingering showers and patchy drizzle tonight

- Above to much above normal temperatures this week

- Fair weather most of the week

&&

.UPDATE...
Issued at 915 PM EDT Sun Sep 15 2019

It would seem to me the low clouds will have a hard time clearing
out tonight due to the light winds and cyclonicly curved low
level winds behind the departing storm system. The nighttime
microphysics satellite loops show the clearing over WI heading
this way. However several runs of the RAP model show the low
clouds just hanging in there overnight. There is some suggestion
in the model sounding that the clouds may try to break up some
after midnight but even if they do we have light winds below 2000
ft on the model sounding and the air is rather moist. Both the RAP
and the NAM show dense fog moving south like a frontal boundary
from north of I-96 by 5 am to I-94 by 8 am. Given there is a
trailing weak cold front behind the departing system that does
make sense. Given the amount of low clouds I am not so willing at
this point to put out a dense fog advisory tonight but it would
not be totally out of the question either.

The light winds tonight into mid morning Monday will make it hard
to mix out the low clouds and fog Monday so it maybe that the
skies will not clear much till early to mid afternoon.

Another issue is there actually are a few showers near I-94
associate with that departing system. These will not be
thunderstorms but just light rain showers. They should be out of
the area by midnight or so. The RAP 00z run shows the 1000/850
moisture transport (weak through it is) into our I-94 counties
till around midnight. After that the moisture transport is focused
on northern IN and OH.

So my bottom line is scattered showers this evening south of
Grand Rapids to Lansing, extensive low clouds into Monday morning
and fog, locally dense near I-94 toward sunrise.



&&

.DISCUSSION...(This evening through next Sunday)
Issued at 300 PM EDT Sun Sep 15 2019

A few light rain showers and patchy drizzle will linger tonight
due to extensive lingering low level moisture and as a mid level
trough moves through early Monday morning. Fair wx is forecast
Monday through mid to late week as an upper level ridge will gradually
build in and amplify over the Great Lakes region.

Temps will undergo a slow moderating trend through the upcoming
week and average around ten degrees above normal for this time of
year early in the week. By mid to late week temps will average
close to 15 degrees above normal for this time of year with high
temps in the upper 70s to lower 80s and min temps mainly in the
60s.

A consensus of latest medium range guidance suggests that fair and
unseasonably warm wx will continue late in the week with the next
chance for rain likely not coming until next weekend.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 825 PM EDT Sun Sep 15 2019

It is that time of year again when the low clouds and fog become
more of a problem and they surely will be tonight into Monday
morning. Currently there is MVFR cigs near and north of I-96 this
evening. Over time as north winds behind the surface wave develop
(in the 06z to 12z) the mixing zone of the cooler moist air with
the warm moist air will result in an area of dense fog along the
surface boundary. If surface winds were stronger the fog would
not be much of an issue with with surface winds under 5 knots I do
believe we will have a zone of dense fog moving south through the
CWA. This is seen on some of our HI RES model visibility forecast
actually and can be seen on model soundings too, via a shallow
saturation zone. So I expect all TAF sites to become IFR or LIFR
by 12z. The fog will likely be thickest with the I-94 TAF sites as
there is where temperature and dewpoint gradient will be
strongest.

Since this is not a strong push of cold air but only as shallow
one with light winds and it is not mid September and our solar
radiation is about half of what it was in June and July, it will
be harder to mix the clouds and fog out. It may take until early
to mid afternoon. I do believe the sky will clear at the northern
sited first and southern TAF sites last (drier air gets to the
northern sites first).


&&

.MARINE...
Issued at 510 PM EDT Sun Sep 15 2019

Looking at surface and marine observations around the area and
also beach cams, it is safe to allow the Small Craft Advisory and
Beach Hazard Statements to expire, so I did.


&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...None.
&&

$$

UPDATE...WDM
SYNOPSIS...Laurens
DISCUSSION...Laurens
AVIATION...WDM
MARINE...WDM



Area Forecast Discussion

National Weather Service Gray ME

 1024 PM EDT Sun Sep 15 2019

.SYNOPSIS...
A weak disturbance will drop south of the region overnight with
a few showers possible along the Massachusetts border. High
pressure builds in to start the week on Monday and remains in
place through the work week and the weekend. A warming trend
begins Thursday with above normal temperatures expected for
Friday and the weekend.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
1020 PM...Showers over the ern zones finally moving out. Once
these showers exit should be dry the rest of the night with
clearing outside the mtns after midnight.

720 PM...As advertised by the HRRR early this evening, line of
light SHRA developing over wrn ME and moving E, these will be
light and may not measure in many spots, and should exit the cWA
by 01Z. May a see a few showers in the mtns longer into this
evening as the weak 500 MB trough passes and exits.

5 PM...Updated the POPS thru early this evening. This covers
the few light showers over the mtns attm and the potential for
a few light showers coming from the area currently over VT and
ern NY. Meso models do show some weakening, but hangs onto a
light band of showers thru about 00Z, so have added some chc
POPS further N, and slt chc pop southward thru the NH lakes
region and across AUG and Belfast.

Previously...Clear skies across the region will give way to
some mid level clouds this evening. Radar reflectivity shows a
shower complex over Lake Ontario this afternoon. Expect these
showers to decay as they move east but have increase PoP along
the Canadian border this evening for anything that is able to
reach the area.

Further south a weak low over Ohio will move east with more
light precipitation passing mainly south of our region with just
a slight chance of rain along the Massachusetts border. Even
with these two very weak features the pattern will be
predominately dry overnight and expect valley fog to form once
again in the CT river valley.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
Monday will begin with the showers passing through the southern
portion of the area and mid level clouds remaining. As the day
goes on expect mostly sunny skies.

Temperatures will be near average on Monday with highs in the
low 70s south to low 60s north. While northwesterly flow will
prevail across most of the region it will be weak enough for a
seabreeze to develop along the immediate shoreline.

Monday night will again see valley fog form as the low level
moisture remains trapped beneath the high pressure.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Overview: Surface high pressure continues to build in from the
west on Tuesday and remains over New England through the long
term period, keeping our region dry and quiet. Temperatures will
be near normal through Thursday but a warming trend will push
them well above normal for Friday and the weekend.

Impacts: No significant impacts anticipated.

Details: Tuesday begins with surface high pressure building in
from the west in the wake of a weak area of low pressure. Broad
surface high pressure then remains over New England through the
rest of the work week, allowing for some dry and comfortable
days as fall approaches. In fact, the best chance for
precipitation over the whole period is not until Sunday when the
latest deterministic guidance shows a frontal system
approaching from the west late in the day.

Temperatures will be near normal through Wednesday with generally
northwest flow aloft. However, an upper level ridge will begin
to push northward into New England on Thursday, starting a
warming trend that will continue into Friday and last through
Sunday. Highs on Wednesday will struggle to reach 70, but by
Friday, some locations in southern NH may reach 80 with
widespread mid to upper 70s expected for much of our region.
Similar high temperatures are expected through the weekend.

Patchy fog will be possible in the river and mountain valleys
early each morning as light winds and mostly clear skies will be
common with the surface high pressure over our region.

&&

.AVIATION /03Z MONDAY THROUGH FRIDAY/...
Short Term... VFR conditions today with just a slight chance for
a few showers along the northern border. After midnight expect
IFR fog to develop in the CT river valley keeping HIE and LEB
fogged in through just after sunrise. A few showers may move
through the mass border early tomorrow but elsewhere VFR with
clearing skies through the region.

Long Term...VFR conditions are generally expected at all
terminals as broad high pressure resides over New England. Winds
will gradually shift from northwest to east to southwest from
Tuesday through Thursday. HIE and LEB can expect periods of IFR
conditions due to fog in the early morning hours each day.

&&

.MARINE...
Short Term... A few showers may pass over the southern waters
tomorrow. Very light northwesterly flow gives way to high
pressure on Monday with no hazardous conditions expected.

Long Term...With high pressure generally dominating the region
and no significant weather systems anticipated, seas and winds
are expected to remain below SCA criteria through Friday
evening. Early Saturday morning may see the arrival of swell
from Humberto and possible SCA conditions for the outer waters.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.

&&

$$
SYNOPSIS...
NEAR TERM...Cempa/Curtis
SHORT TERM...Curtis
LONG TERM...Watson
AVIATION...Curtis/Watson
MARINE...Curtis/Watson




Area Forecast Discussion

National Weather Service Twin Cities/Chanhassen MN

 938 PM CDT Sun Sep 15 2019

.UPDATE...
Issued at 938 PM CDT Sun Sep 15 2019

Still anticipating fog to form this evening up across the Mille
Lacs and Mora areas in MN along with at least our northern and
eastern tiers of counties in western WI. However, have not joined
other Wisconsin offices in putting up a dense fog advisory at this
point as even at Eau Claire, the GFSlamp/LAV and the HRRR have
been trending toward less fog in our eastern CWA, so for that
reason, we are content with just its mention in the HWO at this
point.

&&

.SHORT TERM...(This evening through Monday night)
Issued at 352 PM CDT Sun Sep 15 2019

Fog and low clouds continued to dissipate this afternoon, but it was
slow to lift this morning, especially in east central Minnesota
where locally dense fog persisted through noon. A similar scenario
is possible later tonight in east central Minnesota/west central
Wisconsin as winds remain light and variable. Farther to the west,
winds will start to increase from the southeast in respond to a
storm system moving out into the Plains. Increasing high cloudiness
is also expected as this storm system becomes more organized on
Monday. As moisture and instability increase late Monday night,
along with a strengthening LLJ, a few showers and thunderstorms
could develop across western Minnesota. Temperatures will remain
above normal with highs in the 80s Monday afternoon along with dew
points in the 60s to near 70. Welcome back to summer.

.LONG TERM...(Tuesday through Sunday)
Issued at 352 PM CDT Sun Sep 15 2019

Showers and storms may continue to grow more numerous Tuesday
morning with the LLJ and moisture transport in place and a mid
level disturbance translating northeast across Minnesota. Raised
PoPs to 30 percent over central Minnesota, with slights elsewhere,
but they may need to be increased fairly significantly in later
forecasts if the trend continues. The wave will exit to the
northeast around midday, but persistent moisture transport could
sustain some scattered showers and storms through Tuesday evening.
Some clearing is anticipated by afternoon, and temperatures are
likely to rise back into the 80s area wide, with maybe 90 again in
far west central MN.

A strengthening LLJ Tuesday evening, along with a southeastward
moving cold front, will foster the development of widespread
showers and thunderstorms overnight. Locally heavy rainfall and a
few severe storms are possible, although the best forcing will
shift well north of the area during this time. This will slow the
front for Wednesday, which should eventually stall somewhere
across Wisconsin and Iowa. Chances for showers and storms across
WI and southern/eastern MN are maintained through Wednesday night.

The front will return northward Thursday and Thursday night with
another wave swinging northeast across the Plains from the
southwestern U.S. into Friday. This should be a similar set up to
earlier in the week, except this system appears to be stronger and
isn`t expected to get sheared out. As a result, there will be a
better potential for severe weather Friday and Friday night with
more heavy rainfall also possible.

The front should drive southeast for next weekend bringing a
cooling trend. However, by the following week another system
could emerge over the Plains and bring warmer temps back
northward.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 938 PM CDT Sun Sep 15 2019

Only change to 00z TAFs was to start pulling back on fog mention
at RNH. LAV and HRRR have been trending away from fog potential at
RNH/EAU all evening. Still, with the river next door, have
maintained pessimistic fog forecast for EAU. Nothing has changed
with expectations for Monday, with southeast winds increasing in
strength and high clouds increasing from the west during the day.

KMSP...No additional concerns.

/OUTLOOK FOR KMSP/
Tue...VFR. Chc IFR with TSRA likely late. Wind S at 10-15 kts.
Wed...VFR. Chc MVFR/TSRA. Wind WSW 10-15 kts.
Thu...VFR. Chc TSRA late. Wind SE 5-10 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&

$$

UPDATE...MPG
SHORT TERM...JLT
LONG TERM...BORGHOFF
AVIATION...MPG



Area Forecast Discussion

National Weather Service San Francisco Bay Area

 859 PM PDT Sun Sep 15 2019

.SYNOPSIS...A cold front will spread light rain across much of
our area tonight and Monday, and result in much cooler weather
for inland areas. Tuesday will be dry and mild. A second weather
system may bring scattered showers to the North Bay on Wednesday,
and also keep temperatures on the cool side of normal through
Thursday. Warmer weather is forecast from Friday on into next
weekend.

&&

.DISCUSSION...As of 8:55 PM PDT Sunday...The marine layer rapidly
deepened today as an early season storm system approached from
the northwest. In addition, onshore flow ramped up this afternoon
and locally strong and gusty winds are currently being observed,
primarily near Altamont Pass in the East Bay where winds are
have been gusting as high as 50 mph this evening. The combination
of a deep marine layer and robust onshore flow resulted in
significant inland cooling today, with high temperatures in the
inland valleys and hills cooling by as much as 20 degrees from
yesterday. The only portion of our forecast area that remained
very warm today was the southern interior of Monterey County and
southern San Benito County where highs were in the lower to mid
90s.

Current satellite shows a well defined frontal rain band dropping
south along the northern California coast. Crescent City, on the
far northern California coast, has picked up nearly three-quarters
of an inch of rain (0.72") from this system today. Latest
satellite-derived precipitable water (PW) values remain
relatively impressive, with a narrow band of PWs around 1.5 inches
along the frontal boundary. The models agree that precipitation
potential with the front will decrease as the front pushes south
into a drier airmass. However, given the history of rainfall with
this system, and current satellite data, it seems reasonable to
expect measurable rain across much of the SF Bay Area late tonight
and Monday morning and even some measurable rain as far south as
Monterey and Big Sur by Monday afternoon. Drizzle is already being
reported in San Francisco as low level moisture convergence
increases ahead of the approaching front. Will likely see areas of
drizzle continue near the coast and in the coastal hills prior to
the actual frontal rain band reaching our area later tonight and
Monday morning.

The 00Z NAM shows precipitation along the frontal boundary
dissipating just as the boundary reaches the North Bay late this
evening. But the NAM then forecasts enhancement along the front
as it pushes just to the south of San Francisco shortly after
sunrise on Monday morning. The 18Z GFS shows this enhancement too,
but earlier and farther north. Forecast precipitation totals from
this system are hard to pin down as the models, particularly the
mesoscale models, forecast very spotty QPF, presumably due to
embedded convective elements developing along the frontal
boundary. The latest HRRR forecast values ranging from nothing in
the North Bay Valleys to isolated amounts up to a half inch along
the San Mateo County coast and locally in the East Bay Hills. The
NAM also forecasts up to a half inch in a band from southern San
Mateo County across northern Santa Clara County. The upshot is
that precipitation totals by late tomorrow will likely vary
considerably, and potentially over short distances.

IR satellite is showing lots of cold air behind the incoming front
and models forecast a fair amount of instability along the
frontal boundary late tonight and Monday. But the most unstable
air is projected to be to our east and this is where the Storm
Prediction Center shows a slight risk of thunderstorms on Monday.
If isolated thunderstorms do develop in our area, they would most
likely occur along the eastern fringes of the East Bay.

Dry conditions will return to all areas by late Monday and Tuesday
looks to be a dry and mild day. The next system is forecast to
drop in from the northwest late Tuesday night into Wednesday, and
perhaps generate scattered showers in the North Bay. The midweek
system will have more of an inland trajectory, which could mean
the development of gusty northerly winds on the back side of the
trough Wednesday night into Thursday, mainly in the North and East
Bay Hills.

The midweek system will bring a reinforcing shot of cool air into
our region and keep temperatures on the cool side of normal
through Thursday, especially inland. Warming is then anticipated
late in the work week and into next weekend when the models
generally agree that a ridge will build over California.

&&

.AVIATION...As of 4:19 PM PDT Sunday...It`s VFR at the terminals,
however just beginning to see a few stratus and fog patches already
along coastal Marin and San Mateo counties. Surface to lower level
cooling, a deepening marine layer interacting with increasing water
vapor advancing from the west brings low clouds /MVFR ceilings/
inland with late afternoon and evening sea breezes.

Convergence along a cold front to the NW sweeps southward over the
cwa Monday morning with an amplifying 500 mb trough enhancing upward
vertical motion. The 00z Bay Area tafs advertise wet weather with
light to moderate rain Monday morning quickly turning to vicinity
showers before drier air returns in the afternoon. Patchy drizzle
could develop in lowering ceilings to the south, with very light
rain to light rain band possible far south Monday morning. Ceilings
MVFR tonight and Monday morning except local to areas IFR ceilings
over the North Bay counties and local IFR overnight southward along
the coast.

Vicinity of KSFO...Gusty west wind to 25 knots and VFR until mid
evening. MVFR tonight with light rain arriving by 10z then moderate
rain 13z-18z. Stratus redeveloping in the evening as ongoing cooling
and forcing /lifting along coastal terrain/ and alignment of surface
to lower level west winds bring an inland intrusion of stratus
tonight. Frontal passage occurs Monday morning.

SFO Bridge Approach...Similar to KSFO.

Monterey Bay Terminals...VFR this afternoon then increasing stratus
clouds developing in the early to mid evening. MVFR-IFR ceilings
tonight and Monday morning, patchy drizzle possible tonight. Very
light to light rain arriving late morning and afternoon.

&&

.MARINE...as of 3:43 PM PDT Sunday...Expect locally breezy
afternoon and evening winds along the inner coastal waters south
of Pigeon Point and over the bays. Winds will ease early this week
as high pressure over the eastern Pacific weakens. A cold front
will move through the waters on Monday bringing a chance of
showers. Mixed seas will continue with moderate period northwest
swell and a slightly longer period southerly swell.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .Tngt...SCA...SF Bay until 9 PM
             SCA...Mry 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 until 3 AM

&&

$$

PUBLIC FORECAST: Dykema
AVIATION: Canepa
MARINE: Canepa

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