Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 01/16/22
Area Forecast Discussion
National Weather Service Jacksonville FL
946 PM EST Sat Jan 15 2022
.UPDATE...
Everything remains on track with the rain shield over southwest
Georgia and the Big Bend beginning to move into the Suwannee
Valley. Clouds will lower and thicken over the next few hours with
rain moving from the west to the east. Overall not a lot of
instability for convection but there might be enough lift along
the frontal surface tomorrow morning for isolated to widely
scattered thunderstorms, especially from Jacksonville southward.
With strong southerly winds coinciding with peak high tide
tomorrow morning might see some minor flooding of the usual places
along the St Johns River namely San Marco and Downtown
Jacksonville. Should be very localized and have coordinated with
the city so don`t see the need for any statements. Should be
similar to a high Spring Tide in the San Marco area. That would
entail some street flooding near Landon Circle/Park and the area
near LaSalle Street and Nira Drive/Children`s Way. |
&&
.PREV DISCUSSION [658 PM EST]...
.NEAR TERM [Tonight Through Sunday Morning]...
Tonight, strong low pressure will track north of the area and
bring a warm front north across the area while a strong cold front
approaches from the west. Showers will increase from west to east
after sunset and winds will increase. PWATs ahead of the cold
front are forecast to increase up to 1.5 inches, and locally heavy
rainfall will be possible at times. A few embedded thunderstorms
will be possible tonight, but instability will be limited. The
greatest potential for strong thunderstorms will be closer to the
Gulf Coast where conditions will be a little more favorable.
Sunday morning, showers with a few embedded thunderstorms will
continue and a pre-frontal squall line is expected to move east
across the area. Instability will remain limited, but a strong low
level jet over the area will produce enough wind shear to cause
some organized storms. The SPC has issued a Marginal Risk of
severe thunderstorms from Gainesville to St. Augustine and
southward where a few strong to severe storms will be possible.
The main threats will be strong wind gusts and possible an
isolated tornado. The cold front will move east across the area
Sunday morning, and most precipitation is expected to end by late
morning.
Winds will increase ahead of and behind the front, and a Wind
Advisory has been issued for sustained winds 20-30 mph with gusts
up to 40 mph possible. Locally higher gusts may be possible as
well. The Wind Advisory will be in effect from 6AM to 7PM on
Sunday. A Gale Warning will also be in effect for the coastal
waters from late tonight through late Sunday night/early Monday
morning.
Low temperatures will be mild tonight in the 50s.
.SHORT TERM [Sunday Afternoon Through Monday]...
Sunday afternoon, showers will taper off from west to east,
ending for most areas by noon. A few isolated showers will remain
possible through the afternoon hours. Winds will remain increased
through the day on Sunday, then winds will begin to decrease after
sunset. Colder, drier air will move in as high pressure begins to
build from the west-northwest behind the front. Highs on Sunday
are expected to only reach the upper 50s and 60s due to cloud
cover and precipitation, and Sunday night lows are expected to be
in the middle 30s to lower 40s. Frost is not expected Sunday night
because winds will be too strong.
Monday will be dry and cool with gradually clearing skies
throughout the day. Winds will be a little breezy Monday
afternoon, but weaker than winds on Sunday. High temperatures will
only be in the 50s. Winds will become calm Monday night. Clear
skies and calm winds Monday night will allow temperatures to get
cold. Lows are expected to be in the 30s area wide, SE GA and the
Suwannee Valley will likely see lows below freezing. Freeze and
widespread frost conditions are expected.
.LONG TERM [Tuesday Through Saturday]...
Tuesday through Wednesday, high pressure will remain in place over
the southeast US and dry weather will persist. Another cold front
will approach the area from the northwest on Thursday and is
expected to cross the area on Friday. A mid/upper level trough is
expected to swing across the southern US next weekend, driving
colder air into the region.
Temperatures will be below normal on Tuesday with freeze and frost
conditions possible Tuesday night. Temperatures will increase to
near normal midweek, then decrease below normal towards the end of
the week. We may see freeze and frost conditions again late this
week.
.AVIATION...
[Through 00Z Monday]
Rain shield from our approaching cold front is already in the
Suwannee Valley and will continue to move east impacting local
fields from west to east overnight. Instability for significant
convection should be lacking overnight with the best lift along
the frontal surface in the predawn to early morning hours. Thus
have TS VCNTY about the time of frontal passage tomorrow morning,
generally between 11-15 utc. With steady rainfall and evaporative
cooling saturating the lower atmosphere have opted to drop
ceilings about 5 kft between 8-13 utc to about 1.5-2.5 kft.
windshear will be an issue, especially for general aviation
aircraft ahead of the front and with gusty winds take
off/approaches will be choppy tomorrow afternoon.
.MARINE...
A strong low pressure system will pass north of the area and bring
a strong cold front across the waters tonight into Sunday morning.
The front will bring widespread rainfall and possibly a few
thunderstorms. Winds will increase ahead of and behind the front,
frequent gusts to Gale force are expected late tonight through
Monday morning. A Gale Warning will be in effect from late tonight
through Monday morning. Winds and seas will gradually decrease as
high pressure builds into the region Tuesday and Wednesday.
Another cold front is expected to cross the waters late in the
work week.
Rip Currents: Moderate Risk today, increasing to High Risk
Sunday as winds and waves increase.
.FIRE WEATHER...
A strong cold front will cross the region tonight into Sunday
morning, which will bring widespread rain showers and a slight
chance of thunderstorms. A few strong thunderstorms may be
possible. Increased winds along and behind the front will result
in high daytime dispersions area wide on Sunday. A Wind Advisory
is in effect from 6AM to 7PM Sunday for the whole area for
sustained winds up to 20-30 mph with gusts up to 40 mph possible.
Winds will be lower on Monday, but still strong enough to produce
patches of high daytime dispersions, mainly in SE GA and the
Suwannee Valley. Monday night will be cold, frost and freeze
conditions will be possible.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 50 58 36 52 30 / 100 100 0 0 0
SSI 55 64 40 54 35 / 90 100 0 0 0
JAX 54 64 39 56 34 / 90 100 0 0 0
SGJ 56 68 40 57 38 / 60 100 0 0 0
GNV 54 63 38 56 33 / 100 100 0 0 0
OCF 56 64 41 58 33 / 90 100 0 0 0
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Wind Advisory from 6 AM to 7 PM EST Sunday for Baker-Bradford-
Central Marion-Coastal Duval-Coastal Flagler-Coastal Nassau-
Coastal St. Johns-Eastern Alachua-Eastern Clay-Eastern
Marion-Eastern Putnam-Gilchrist-Hamilton-Inland Flagler-
Inland Nassau-Inland St. Johns-Northern Columbia-South
Central Duval-Southern Columbia-Suwannee-Trout River-Union-
Western Alachua-Western Clay-Western Duval-Western Marion-
Western Putnam.
GA...Wind Advisory from 6 AM to 7 PM EST Sunday for Appling-Atkinson-
Bacon-Brantley-Clinch-Coastal Camden-Coastal Glynn-Coffee-
Echols-Inland Camden-Inland Glynn-Jeff Davis-Northeastern
Charlton-Northern Ware-Pierce-Southern Ware-Wayne-Western
Charlton.
AM...Gale Warning from 3 AM Sunday to 10 AM EST Monday for Waters
from Altamaha Sound GA to Fernandina Beach FL from 20 to 60
NM-Waters from Fernandina Beach to St. Augustine FL from 20
to 60 NM-Waters from St. Augustine to Flagler Beach FL from
20 to 60 NM.
Gale Warning from 3 AM Sunday to 4 AM EST Monday for Coastal
waters from Altamaha Sound to Fernandina Beach FL out 20 NM-
Coastal waters from Fernandina Beach to St. Augustine FL
out 20 NM-Coastal waters from St. Augustine to Flagler
Beach FL out 20 NM.
&&
Area Forecast Discussion
National Weather Service Phoenix AZ
454 PM MST Sat Jan 15 2022
.UPDATE...
Updated Aviation discussion.
&&
.SYNOPSIS...Breezy conditions will persist through this afternoon,
especially across the Arizona high terrain. Periods of high clouds
will move into the area through early next week. Generally dry
conditions along with above normal temperatures can be expected
through next week.
&&
.DISCUSSION...
Breezy conditions are currently being observed from southeast to
west-central Arizona with wind gusts ranging between 20-30 mph
with locally higher gusts, especially across the higher terrain.
These higher winds are in response to an enhanced pressure
gradient resulting from a strong surface high pressure located
over the intermountain region. These enhanced wind gusts will
continue through the rest of this afternoon and diminish by
sunset, with significantly weaker winds expected on Sunday as the
pressure gradient weakens.
Meanwhile, latest objective analysis shows a high pressure aloft
situated over the western third of the United States with a cutoff
low situated off the California coast. This cutoff low is sending
mid to high level cloudiness into the area, with the thicker
cloud deck limited to above 20 kft. Below that layer, very dry low
to mid tropospheric air exists as evidenced by the latest Phoenix
ACARS sounding due to strong subsidence from the aforementioned
high pressure aloft. The thicker cloud layer aloft will likely
hold back max temperatures a few degrees for today compared to
yesterday, with highs likely topping out in the upper 60s to lower
70s.
The overall synoptic pattern is expected to remain unchanged during
the next couple days with ridging aloft holding firm over the
western third of the United States and the cutoff low remaining
stationary off the California Coast. Then, by late Monday into
Tuesday, as a shortwave trough digs from western Canada into the
northern United States, the aforementioned cutoff low will
finally begin to make its trek eastward towards the area, although
in a much weakened state as it opens up into a wave. Some
ensemble members, especially the ones from the ECMWF suite, are
indicating some light measurable rain over the area. The NBM
continues to have only 10-15% PoPs. However, the environment does
not appear to be overly conducive to rain as there is limited
moisture in the low-levels and a general lack of forcing.
As we head into the middle to latter half of next week, there is
very strong agreement amongst the ensemble clusters of a strong
Rex Block setting up off the west coast. The overall setup may
allow for a couple of subtle shortwave troughs to overtop the
ridge and dive southward into the southwest CONUS. However, there
is uncertainty amongst the ensemble suites as to whether or not
one of these shortwaves will develop into another cutoff low west
of the area by the end of next week into next weekend. At this
time, about a third of the GEFS members show this scenario of
another cutoff low developing while most of the EPS members do not
show it. The scenario of another cutoff low west of the area
would introduce precip chances once again. At this time, the NBM
PoPs at the end of next week into next weekend is less than 10%.
Lastly, temperatures will likely remain above average through most
of next week with highs topping out in the lower to middle 70s.
There is even a possibility of upper 70s by next weekend as depicted
by the upper end of the NBM guidance if the cutoff low scenario does
not materialize as currently depicted by the EPS solution.
&&
.AVIATION...Updated 2354Z.
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Easterly winds in the lower half of the troposphere will trend
toward southeasterly tonight and Sunday. Easterly surface winds
have weakened from earlier today and are expected to favor
nocturnal downvalley patterns after 03Z. Above the near surface
inversion but within 2kft AGL, easterly winds of 15-20 kts are
anticipated (not enough difference to meet LLWS criteria). As for
sky cover, an upper low centered west of San Diego will continue
to spread thick cirrus across the area tonight before thinning out
considerably by afternoon.
Southeast California/Southwest Arizona including KIPL and KBLH:
North and northeasterly flow in the lowest 3-5kft ASL will
continue through Sunday. At the surface, light winds with a
westerly component will continue at KIPL through Sunday morning
before transitioning to light northerly in the afternoon. At KBLH,
northerly winds of around 10 kts will weaken during the evening
and become light west after 10Z or so before northerly winds
resume in the afternoon. As for sky cover, an upper low centered
west of San Diego has been overspreading the area with thick
cirrus. Cloud cover will begin to thin out from southwest to
northeast this evening.
&&
.FIRE WEATHER...
Monday through Friday:
Generally dry conditions with warmer than normal temperatures are
expected through the period. A weak disturbance will move through
the region on Tuesday bringing a 15% chance for light showers over
the Arizona high terrain, but wetting rains are not expected. High
pressure centered to the west is then likely to dominate the rest
of the period. Minimum afternoon humidity levels will initially
range from 15-25% on Monday, but then increase to 25-35% for
Tuesday and Wednesday. Drying conditions are then likely late in
the period dropping Min RHs back down to 15-25%. Winds will
overall be fairly light through the period, but some daytime
breeziness may result in gusts to around 20 mph late in the period.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
DISCUSSION...Lojero/Kuhlman
AVIATION...AJ
FIRE WEATHER...Kuhlman