Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/18/18
Area Forecast Discussion
National Weather Service Wakefield VA
759 PM EDT Sat Mar 17 2018
.SYNOPSIS...
Low pressure moves across North Carolina overnight. High
pressure builds into the area Sunday, then moves offshore Sunday
night. A trio of low pressure systems are expected to impact
the region Monday through Wednesday.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Initial (light) pcpn moved off the coast earlier this eve. Sfc
warm front tried to move N into far SSW areas of FA this
eve...but stopped just before it did so. Now...the RAP indicates
that boundary slowly settles back S overnight as sfc lo pres
tracks along it (across NC). Area of SHRAs/ISOLD tstms moving
through srn WV/far SW VA attm. Near term models and trends
suggest that that area will be tracking ESE overnight. Would
rule out a rumble or two of thunder (from potential ISOLD elevated
stms) far SW and over NE NC...otherwise bulk of any tstms
should remain S of the FA. Will carry highest PoPs (50-60%)
across far srn VA and into NE NC...tapering to 10% or less NE
quarter of the FA. A gradually lowering of the PoPs begins later
tonight as lo pres exits the NC coast (S of HSE). Lows from the
l30s N to the u30s- around 40F far S and SE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
Dry with near seasonable temps Sun as weak high pres moves across
the area. Mstly sunny. Highs 50-55 along the coast, 55-60 west of
the bay. The high moves off the coast Sun night. Mstly clr except
for some incrg clouds across the piedmont. Lows in the 30s.
The high pushes farther offshore Monday and will be quickly followed
by overrunning pcpn leading to a weak or in-situ CAD setup across
the region during the aftrn. Meanwhile, a potent s/w races eastward
from the southern plains in the morning into the TN Valley by late
in the day. Cut back pops a bit through 18Z and confined them to the
wrn and srn most zones due to weak upslope flow. Light rain expected
to break out and overspread areas west of the bay in the aftrn. QPF
amounts during Monday generally aob one tenth inch. Highs 45-50 ern
shore and through the 50s west of the bay.
A widespread rain is expected Mon night as the s/w reaches the mts
by 12z Tue. Categorical pops all areas with some mdt rainfall psbl
aftr midnight. Lows mid 30s north to mid 40s south.
A sfc low organizes over the Carolinas Monday night before emerging
off the mid-Atlantic coast and deepening Tuesday morning. Will carry
likely to categorical PoPs Tues morning as the best lift shifts east
by 18Z. Chc pops west with likely east Tue aftrn. Highs 40-45 north,
50-55 se coastal areas.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
The first few days of Spring will be more like Winter as
deep/anomalous trough sets up invof ern CONUS. Using a blend of
WPC/GFS/ECMWF the extended periods. Initial lo pres pulls slowly
away from the coast Tue night...w/ trailing upper level system
diving through the region Wed (w/ secondary lo pres developing invof
SE VA-NC coasts). Partial thickness scheme gives rather hi potential
for mixed ptype (SN/RA over many inland locations...mainly Wed/Wed
eve). Way too soon to speculate on if/any accums. Drying out/chilly
Wed night-Thu...remaining so through Fri. After that...the next lo
pres system expected to approach from the W by Sat (bringing at
least increasing cloudiness).
Lows Tue night in the l-m30s inland...u30s/around 40F far SE VA-NE
NC. Highs Wed in the u30s inland...l40s coastal SE VA-NE NC. Lows
Wed night in the u20s W to the m30s right at the coast. Highs Thu
ranging through the 40s. Lows Thu night in the u20s W...m30s at the
coast. Highs Fri around 50F W...m-u40s elsewhere. Highs Sat in the
l50s inland...m-u40s at the coast.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR conditions continue across the region at 00Z with sct/bkn
mid and high clouds and mostly light winds that vary from NW to
NE. A stationary frontal boundary lies just south of the CWA
border. A shortwave is moving through KY and bringing an area
of showers which is generally riding along the frontal boundary
from eastern KY into southwestern VA. The showers are expected
to mostly affect the extreme southern portions of our CWA but
scattered showers may also get into central and SE VA during the
overnight hours. An isolated tstm is also possible especially
for NE NC. The shortwave should push off the coast by sunrise
Sunday and take any showers/tstms along with it. Expect mostly
VFR conditions for Sunday.
Outlook: Another window of flight restrictions late Mon thru
Wed as a trio of low pressure systems impact the area. Rain for
the most part may mix with or change to wet snow by Wed at
RIC/SBY.
&&
.MARINE...
Current observations show E/SE winds of 10 to 15 knots over a
majority of the waters this afternoon. Seas average 2 to 3 feet and
waves average 1 to 2 feet or less. A surface low is expected to move
across portions of southern VA and NE NC later tonight. As the low
moves off the coast NC coast late tonight into Sunday morning, will
see a bit of surge in NNE winds to ~15 knots. Still am not
anticipating SCA headlines due to very limited cold air, but would
not be surprised to see a few gusts in excess of 20 knots. Winds
diminish to 5 to 10 knots or less Sunday afternoon while shifting to
the east and then to the south Sunday night.
Conditions become much more unsettled Monday night through at least
midweek as the next low pressure system approaches from the TN
Valley, then is progged to re-develop as a coastal low off the Mid-
Atlantic coast Tuesday. The first low pushes off to the NE Tuesday
afternoon and evening with yet another low expected to develop off
the SE Coast and then rapidly intensify while pushing NE off the Mid-
Atlantic coast Wednesday night. Still looking as though strong SCA
conditions appear Monday night through Wednesday with a period of
Gales even a possibility Tuesday night and again Wednesday into
Wednesday night depending on the exact track of these systems.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...None.
&&
$$
SYNOPSIS...ALB/MPR
NEAR TERM...ALB/MPR
SHORT TERM...JDM/MPR
LONG TERM...ALB
AVIATION...MPR/JEF
MARINE...AJB/LKB
Area Forecast Discussion
National Weather Service Bismarck ND
944 PM CDT Sat Mar 17 2018
.UPDATE...
Issued at 942 PM CDT Sat Mar 17 2018
Clearing across central ND persists. Used a blend of the last two
HRRR iterations for sky grids, which is similar to the RAP/NAM in
filling in this clear area with clouds between 06-09Z. No other
changes at this time.
UPDATE
Issued at 640 PM CDT Sat Mar 17 2018
Sky cover was adjusted with a rather large hole in the stratus
deck over portions of western and central ND currently. This hole
will fill in this evening along with fog developing. Temperatures
were adjusted upwards with cloud cover tonight keeping values from
dropping too much. Otherwise edits to the forecast were minor.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 243 PM CDT Sat Mar 17 2018
The main focus for the short term is fog tonight and mixed
precipitation developing afternoon tomorrow.
Tonight, warmer and more moist air starts to be advected in. Low
stratus is already forming across southwest North Dakota in
response to this return flow. Low stratus will continue to develop
and overspread most of western and central North Dakota tonight.
An upslope component to the winds will further aid in the
development of stratus and eventually fog late tonight. Fog may
become dense in some of the valleys later tonight.
Tomorrow, the next storm system approaches North Dakota. Several
small upper level waves will rotate around the main upper level
circulation currently located in the Pacific Northwest. One such
wave will swing through southwest North Dakota Sunday afternoon.
This will combine with developing frontogenesis to spark an area
of precipitation oriented southwest to northeast across western
North Dakota. The evening hours on Sunday will see a period where
there is support for banded precipitation with frontogenesis, an
upper level jet streak and fairly steep mid level lapse rates. The
period of highest precipitation rates will be late Sunday
afternoon and Sunday night. With temperatures in the critical
threshold of mid 30s there could be mix of rain, freezing drizzle
and snow Sunday afternoon and evening.
.LONG TERM...(Sunday night through Saturday)
Issued at 243 PM CDT Sat Mar 17 2018
The focus in the extended will be the Sunday and Monday period.
There continues to be some uncertainty in the snow amounts,
however, we are seeing convergence on a location of highest
accumulation. It appears west central North Dakota, locations
generally between Bismarck and Dickinson, will see the highest
accumulations. There appears to be a good chance for at least four
inches over west central North Dakota for Sunday night and
Monday. We continued the Special Weather Statement, with headlines
possible later tonight/tomorrow.
Tuesday through Thursday will see a building ridge across the
Northern Plains which will suppress precipitation, but another
rather robust negatively tilted upper low is forecast to move from
the northwest US into the Northern Plains by Friday. This will
provide another opportunity for precipitation, both rain and snow.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 942 PM CDT Sat Mar 17 2018
Widespread MVFR cigs remain over much of western and central
North Dakota. There remains a large hole in the stratus across
central North Dakota, but this should fill in after 06Z-09Z.
IFR/LIFR cigs and vis overnight into Sunday morning as stratus
lowers and fog develops.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...NH
Area Forecast Discussion
National Weather Service El Paso Tx/Santa Teresa NM
321 PM MDT Sat Mar 17 2018
.SYNOPSIS...
Looks like a windy week ahead for the Borderland as several
impulses pass through. The first one is an upper trough passing
across northern New Mexico Sunday. This will bring strong winds of
25 to 35 mph to the area, along with blowing dust. Monday through
Wednesday will be quieter with no significant winds, though
temperatures will be cooler. Then Thursday through the weekend,
strong winds will develop again as a series of upper troughs move
across northern New Mexico and the central Rockies. Winds will be
mostly 20 to 30 mph each day, with some blowing dust. Temperatures
will warm to well above normal.
&&
.DISCUSSION...
What do you know-it`s March and it`s windy. This week is looking
windy for the majority of the time as several upper troughs sweep
across the CWA. In the short term, an upper low continues to churn
over the Pac Northwest. Ahead of it, a shortwave trough is passing
through central New Mexico as we speak, with a plume of moisture
associated with it. This plume is mostly higher level moisture as
PWs are only around .3 to .4 inches. NAM and HRR both showing some
convection developing over northern Mexico and move into west
Texas tonight. Kept a low POP in for Hudspeth, but HRRR continues
to show showers into El Paso county too. Mid level winds on
satellite look pretty stout, though some CU and maybe TCU are
forming over northern Mexico. will have to watch this over the
next several hours.
Sunday...upper trough swings across northern New Mexico. Moderate
lee side cyclogenesis develops over SE Colorado, with surface
trough down across far eastern New Mexico. Gradient and model lower
level winds of 30-35 mph suggest lower rung wind advisory. Will
issue NPW shortly for Sunday afternoon and early evening. Could be
some dense blowing dust, though relatively early fropa and cold
advection may help knock the dust down earlier than usual. Front
could produce a few showers over the Gila as it moves through
Sunday morning.
Monday through Wednesday...no significant weather as we sit in
zonal flow under a low amplitude ridge. Temperatures will be on
the cooler side, just below normal.
Thursday through the weekend...returns to more winds as large
Pacific low drags a series of troughs onshore. Increased southwest
flow will induce lee side cyclogenesis over SE Colorado again.
Expect breezy afternoons each day as surface pressure gradient
tightens, though at this time winds look to remain below advisory
level. Plenty of time for changes though. Warm advection from
southwest flow will push temperatures well above normal, with
warmest temperatures of the season likely.
&&
.AVIATION...Valid 18/00Z-19/00Z...
VFR conditions will continue thru the TAF period. However some
reduction in visibility will be possible after 18Z due to
localized BLDU. Expect P6SM FEW-SCT100 SCT-BKN250 with SW winds
continuing. Expect winds 12 to 15 knots gusting 20 to 25 knots
through 18Z. After 18Z look for increasing SW winds of 25 to 30
knots gusting 35 to 40 knots.
&&
.FIRE WEATHER...
An approaching upper disturbance will bring stronger winds to the
area tonight and Sunday. However, temperatures will be a few degrees
cooler Sunday, resulting in min RH values above critical thresholds
through the day tomorrow. Mainly dry conditions will be the rule
with this system with the exception of some isolated thunder over
far eastern Hudspeth county tonight and a few stray showers over
northwestern fire zones early Sunday. Warm conditions will return
during the week ahead with a continuation of dry surface conditions.
Lowland Min RH values will run between 10 and 15 percent through the
week. This combined with increasing winds Thursday into the weekend
could result in critical fire weather conditions across the region
later in the extended period.
&&
.PRELIMINARY POINT TEMPS/POPS...
El Paso 51 65 42 64 / 0 0 0 0
Sierra Blanca 48 66 38 63 / 10 0 0 0
Las Cruces 44 62 35 62 / 0 0 0 0
Alamogordo 45 62 36 60 / 0 0 0 0
Cloudcroft 33 42 24 44 / 0 0 0 0
Truth or Consequences 42 60 34 61 / 0 0 0 0
Silver City 36 50 30 56 / 0 10 0 0
Deming 42 60 32 62 / 0 0 0 0
Lordsburg 39 58 32 60 / 0 10 0 0
West El Paso Metro 50 64 41 63 / 0 0 0 0
Dell City 46 68 37 66 / 0 0 0 0
Fort Hancock 50 69 41 66 / 10 0 0 0
Loma Linda 47 61 38 60 / 0 0 0 0
Fabens 48 67 40 65 / 0 0 0 0
Santa Teresa 47 64 39 63 / 0 0 0 0
White Sands HQ 47 63 38 62 / 0 0 0 0
Jornada Range 43 62 32 62 / 0 0 0 0
Hatch 43 63 32 64 / 0 0 0 0
Columbus 45 63 36 63 / 0 0 0 0
Orogrande 48 64 38 62 / 0 0 0 0
Mayhill 39 52 31 53 / 0 0 0 0
Mescalero 38 51 30 52 / 0 0 0 0
Timberon 38 50 29 50 / 0 0 0 0
Winston 36 52 31 56 / 0 10 0 0
Hillsboro 40 56 33 60 / 0 0 0 0
Spaceport 41 61 32 61 / 0 0 0 0
Lake Roberts 34 49 28 56 / 0 10 0 0
Hurley 36 53 29 58 / 0 10 0 0
Cliff 32 55 24 58 / 0 10 0 0
Mule Creek 33 52 24 58 / 0 20 0 0
Faywood 38 55 31 59 / 0 10 0 0
Animas 39 60 33 63 / 0 10 0 0
Hachita 40 60 32 62 / 0 0 0 0
Antelope Wells 41 63 33 64 / 0 0 0 0
Cloverdale 39 57 35 61 / 0 0 0 0
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...Wind Advisory from noon to 8 PM MDT Sunday for NMZ402>417.
TX...Wind Advisory from noon to 8 PM MDT Sunday for TXZ418>424.
&&
$$
Hefner/Laney
Area Forecast Discussion
National Weather Service Goodland KS
603 PM MDT Sat Mar 17 2018
.SHORT TERM...(This evening through Monday night)
Issued at 315 PM MDT Sat Mar 17 2018
Tonight-Sunday...some mid and high clouds move into the area from
the southwest with possibly a thick deck of cirrus toward sunrise.
The latest high res guidance is showing stratus moving southwest
into parts of our area with sharply reduced visibilities, starting
around 07z-08z and continuing through mid morning Sunday. Have
added areas of fog accordingly. Southeast winds 5 to 15 mph
tonight with lows in the upper 20s to mid 30s.
On Sunday mid level dry slot moves into the area from the
southwest and should help in preventing any thunderstorm activity
til perhaps the very late afternoon and closer to sunset when low
pressure emerges over southeast Colorado associated with a larger
upper trough. Enough moisture may be present to generate showers
and thunderstorms generally west of a line from about Yuma to
Colby and Oakley initially, slowly expanding in coverage though
sunset. Winds increase into the breezy to windy category from the
southeast during the day. High temperatures in the low to upper
60s.
Sunday night-Monday night...models maintain a forecast track taking
the center of the storm system east along the Kansas/Oklahoma border
through Monday morning. Showers and thunderstorms increase in
coverage through midnight with a change over to snow from west to
east as colder air filters in behind the storm. North winds increase
into the 15 to 30 mph range with higher gusts, strongest winds
generally along and west of the CO/KS border. This will likely
produce some reduced visibilities in snow and blowing snow.
For Monday the storm system is well east of the area but we`re under
the impact of an upper trough which will contribute to additional
snow or a mix of rain and snow in the morning. Question is will
temperatures warm enough in the afternoon to completely change the
precip type to liquid or like on Friday keep temperatures under the
stronger dynamics favorable for snow. I trended temperatures down a
few degrees prolonging potential for snow but it may not be enough.
Right now the afternoon has mainly rain as precip type. Currently
have high temperatures in the upper 30s to low 40s. Winds will
continue from the north in the 15 to 25 mph range with higher gusts.
Precipitation comes to an end from west to east by midnight as drier
air moves in. Little if any additional moisture is expected. Low
temperatures look to range from the upper teens to low 20s west,
low to mid 20s east of the CO/KS border.
Right now total snowfall accumulations range from a trace to 3
inches, highest in Yuma county. ECWMF/SREF/GFS/NAM 24 hour snowfall
amounts are quite a bit higher. Experimental HRRR snowfall amounts
similar to current forecast. CIPS analogs also show high
probabilities of 2 inch amounts with very little support for
anything over 4 inches. Am hesitant to make any adjustments up or
down from current forecast given at least continuity between model
runs and neighboring offices. Still have time to adjust if need be.
.LONG TERM...(Tuesday through next Saturday)
Issued at 145 PM MDT Sat Mar 17 2018
Upper ridge over the Great Basin Tuesday will move east and
amplify as it approaches the Plains on Thursday. A fast moving,
weak shortwave trough will come through on Friday as the ridge
moves east. Models have gone dry with this system, apparently due
to a lack of moisture. So, the extended period is currently dry.
Temperatures will start near normal on Tuesday and warm to much
above normal by Thursday and Friday, then cool off a bit for
Saturday behind a cold front associated with the shortwave. Only
hazardous weather potential will occur on Friday, with critical
fire weather conditions possible due to low humidity and gusty
westerly winds.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 600 PM MDT Sat Mar 17 2018
VFR conditions will generally prevail through the 00Z TAF period,
aside from a short period of MVFR/IFR stratus possible at the KMCK
terminal Sunday morning, primarily between 12-16Z. Somewhat breezy
SSE winds (15-20 knots with gusts to 25-30 knots) are expected to
prevail at the KGLD terminal overnight through Sunday morning,
strengthening to 20-25 knots with gusts up to 35 knots during the
afternoon. Winds are expected to back from SSE to SE very near the
end of the TAF period at KGLD. At KMCK, expect ESE winds at 8-13
knots overnight/Sunday morning to veer to the SE at 15-18 knots
with gusts up to 25-28 knots by early afternoon (~18Z). By the end
of the 00Z TAF period, winds at KMCK will back to the ESE and
strengthen to 20-25 knots with gusts up to 30-35 knots.
&&
.FIRE WEATHER...
Issued at 315 PM MDT Sat Mar 17 2018
Critical/near critical fire weather conditions are possible Sunday
afternoon as relative humidity values below 20 percent and south
to southeast winds gusting 20 to 25 mph combine generally along
and south of a line from near Flagler to Cheyenne Wells to near
Tribune.
Critical and near critical fire weather conditions remain possible
Friday afternoon as relative humidity values in the 10-15 percent
range combine with west and northwest winds gusting to 30 mph
along and south of a line from Flagler to Burlington to Russell
Springs.
Critical fire conditions are possible Saturday afternoon from
Flagler to Tribune and points west.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...99
LONG TERM...ERRYK
AVIATION...VINCENT
FIRE WEATHER...99
Area Forecast Discussion
National Weather Service Wilmington NC
1041 PM EDT Sat Mar 17 2018
.SYNOPSIS...
Mild temperatures will prevail tonight ahead of an
approaching cold front, that will cross the coast early Sunday.
Lingering clouds and slightly cooler temperatures will be
featured on Sunday. A warming trend can be expected early next
week as a storm system approaches. Periods of rain and showers
Monday night through Wednesday, may transition to light snow
Wednesday night before drier air sets in Thursday. Accumulations are
not expected because of the relatively warmer ground. A low pressure
system will approach the coast next weekend.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 1000 PM Saturday...Concern overnight involves a potent
shortwave evident on WV imagery moving overhead the Appalachians,
and how its interaction with a surface cold front will impact
convection overnight.
Latest regional mosaic shows an area of strong to severe
thunderstorms cresting the TN/NC/SC mountains and moving quickly
to the ESE. This is in response to the aforementioned shortwave,
and Although SPC has dropped the SLGT risk to our north, the
MRGL risk has been expanded to include the extreme northern tier
of the CWA. While the potential exists for thunderstorms
overnight, it appears the severe risk is low due to the elevated
nature of instability. Latest RAP soundings show 600-1000 J/kg
of MUCape for parcels near 900mb, enough to sustain convection,
but a stable surface layer should preclude any of the strong
winds aloft from mixing down. However, there is a small area,
mostly from Lumberton to Wilmington, where the high-res guidance
suite, including the RAP, HRRR, NSSL WRF, and ARW, all paint
some convection moving across beneath the upper vort and along
the front. This is due to a ribbon of the slightly better
instability correlating with higher moisture content and
stronger forcing. Have increased POP to mid-chc northern tier
and schc along the SC/NC border, but again, the severe threat
looks minimal. Cannot rule out an elevated hailer, but the
primary threat will be briefly heavy rain and some lightning,
focused from about 2am near Lumberton, to 7am near Wilmington,
and then moving offshore.
A weak surface wave beneath the potent vort will exit offshore
very late tonight or early on Sunday, and this will act to pull
the cold front to the south. Behind this front temps will drop
quickly and some stratus will develop, but exactly where this
front settles will determine the sharp temperature gradient due
to much warmer (cooler) temperatures on the south (north) side.
Have tried to show this with upper 40s by daybreak Sunday far
northern tier, while remaining in the mid 50s near the South
Santee River. Relevant portion of previous discussion below:
As of 344 PM Saturday...Southwest winds will veer around to the
north behind front as it drops south through the area early Sun
morning. Any lingering chc of pcp through the morning will lead
to drying by Sun afternoon. Pcp water values up near 1.4 inches
ahead of the front will drop to near a half inch air mass
clears out in drier northerly flow as high pressure builds in.
Max temps on Sunday will be near 60 over SE NC, but will reach
closer to 70 in NE SC.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
As of 344 PM Saturday...ECMWF/GFS both show an upper low across
the Central Plains Sunday night. The upper low is progged to
translate across the MS Valley during Monday evening. At the
surface, a cold front will be aligned south of the forecast area
at the onset. In the meantime, an area of isentropic lift and
increasing low-level theta-E advection will bring rainfall
chances back into the area Sunday night. Mentioned a slight
chance of thunderstorms as well with some elevated instability
present late Sunday night into Monday morning, primarily for SC
zones. By early Monday evening both GFS/ECMWF position a surface
low across TN with the warm front returning north across the
area with decent rainfall chances continuing. Included
thunderstorms during this time frame as stability decreases
across the area. The ECMWF tracks the low a little further
south, but given either solution our rainfall chances will be on
the high end across the forecast area. Blend of MAV/MET numbers
appears reasonable through the period. Would not be surprised
to see the convective risk areas shifted a little farther north
for Monday, but the bulk of the instability will likely stay
farther south.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 344 PM Saturday...Low pressure pulling off the coast will
bring a lull Tuesday, before another low develops and brings
periods of showers Tuesday night through Wednesday, changing
over to snow or a rain/snow mix Wednesday evening. Forecast low
temperatures and thermal profiles, depict a brief period of
frozen precipitation is possible across much of the area. Sharp mid-
level drying will end PCPN prior to daybreak Thursday. Significant
accumulations are not expected due to warmer ground, but a "Frost`
advisory, or `Freeze Warning` may be needed very early Thursday,
favored over interior SE NC, but could reach into parts of NE SC.
Did not include thunder this period because of stable/cooler low
levels, but elevated instability will exist to some degree. QPF Tue-
Wed night averages to 3/10" to 5/10".
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
As of 23Z...Frontal boundary extends from the Outer Banks to
western VA into eastern TN early this evening. As the boundary moves
into the area overnight and early Sunday morning a few of the
terminals may experience scattered showers and possibly an isolated
thunderstorm. Best chance at KFLO and KLBT in the 06-08Z range and
08-10Z at the coastal terminals. A round of stratus in the wake of
the front may cause IFR CIGS for a few hours in the morning before a
drier column takes hold and clearing occurs thereafter.
Extended outlook...Periods of MVFR Sunday through Wednesday. Chances
for convection increasing Monday through Tuesday.
&&
.MARINE...
NEAR TERM /THROUGH SUNDAY/...
As of 1000 PM Saturday...Front to the north will waver in the
vicinity until a shortwave and weak low pressure move along it
and offshore by the morning. This will drag the front southward
and turn winds to the N/NW. However, this is not likely to occur
until first thing Sunday, and most of the local waters will
remain entrenched in gusty SW winds of 15-20 kts through the
overnight, persisting seas at 3-5 ft. Relevant portion of
previous discussion below:
As of 344 PM Saturday...Winds will veer around toward daybreak
quite rapidly to the W-NW and then N, with speeds increasing
after a brief reprieve back to 10-15 kts. Seas will basically be
in the 2 to 4 ft range, but expect a few 5 fters in the outer
waters off of Cape Fear heading out toward Frying Pan Shoals.
Looks like seas should remain below any criteria for SCEC or
SCA.
SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
As of 344 PM Saturday...Weak high pressure across eastern NC at
the beginning of the period will shift eastward Monday
morning. A stalled front south of the waters will begin to lift
north as another area of low pressure takes shape across the MS
Valley. The initial easterly wind will veer to a southeasterly
direction Monday morning. Additional veering is expected as low
pressure moves across NC Monday night. Thus a stronger southwest
fetch will develop with Small Craft Advisory conditions
possible overnight Monday. Seas will be highest in the southwest
fetch late Monday night.
LONG TERM /TUESDAY THROUGH THURSDAY/...
As of 344 PM Saturday...This is shaping up to be a difficult
marine period, as a series of strong low pressure systems impact
the coast. Gusty SW winds 20-25 KT Tuesday and Tuesday night,
will shift to north equally strong, if not stronger Wednesday
as N and NW winds kick up in a cold air surge. Gusts to near
Gale force are not out of the question Wednesday over the outer
waters, with current numerical wave guidance at FPSN7 assigning 7
feet Wednesday. Very cold temperatures will greet mariners early
Thursday, in a moderate, but biting, offshore wind.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...
NEAR TERM...JDW/RGZ
SHORT TERM...SRP
LONG TERM...MJC
AVIATION...SRP
MARINE...
Area Forecast Discussion
National Weather Service Lincoln IL
915 PM CDT Sat Mar 17 2018
.UPDATE...
Issued at 900 PM CDT Sat Mar 17 2018
Drier air is beginning to filter in across central and southeast
Illinois from the north in the wake of the system that passed
through the Midwest earlier today. While the arrival of this drier
air and departure of forcing with the system has ended the
precipitation risk, tonight`s forecast is still a little tricky.
Skies across the forecast area have started to clear from the
north, and this clearing should continue to expand southward
overnight. The ground surface is wet across most of the area due
to precipitation that occurred over the past 24 hours. This fact,
combined with light winds and clearing skies would seem to be a
good setup for fog later tonight. Most of the high resolution
guidance suggests light fog development later tonight, with
pockets of locally dense fog. Guidance generally suggests the
thickest fog will be over southwest portion of the forecast area,
which will also be one of the last areas to clear. Would generally
expect areas that clear sooner to have thicker fog since they have
longer for radiational cooling and associated saturation to occur.
Going forecast already had mention of patchy fog and see no reason
to deviate from this right now. Plan to update forecast for the
latest hourly trends (mainly sky cover). Can`t rule out the need
for stronger fog mention or possibly an advisory before morning,
but confidence is not high enough to adjust at this time.
&&
.SHORT TERM...(This evening through Sunday)
ISSUED AT 303 PM CDT Sat Mar 17 2018
Ridging at the surface and aloft over the Plains this afternoon,
keeping a northerly component in the winds over the forecast area.
Cooler air filtering into the region, but the stubborn stratus
associated with the low passing through the Midwest into IN this
afternoon is slow to erode. HRRR slowly progresses this shield of
clouds to the south tonight, eventually moving to mostly clear for
Central IL by morning. Concerned that the dry air is a little
further to the north than prev forecast...in addition to the fact
that there is not significant llvl flow to change the airmass
quickly. Lighter winds in the overnight combined with llvl
moisture still trapped in the low levels may slow the progression
of the low clouds to the southwest. There is currently a good 30
mile or so lag of the dry air behind the clearing line to the
north/northeast. With that in mind, have put patchy fog in the
forecast after midnight for where the clearing is anticipated.
Should the delay last longer, there is a potential for some of
that fog to become dense...but guidance winds stay up just enough
to drop confidence in that for now. Tomorrow, mild temps with
highs in the 50s. The swath of low clouds holding just to the
southwest with light easterly winds attempting to advect some of
that drier air in at the surface. How far south those clouds get
will greatly impact temperatures particularly SW of a line from
Macomb to Decatur.
.LONG TERM...(Sunday night through Saturday)
ISSUED AT 303 PM CDT Sat Mar 17 2018
Overnight Sunday into Monday...lows drop only to the low to mid
40s as increasing clouds once again inhibit cooling in the
overnight hours. Next system for Monday/Monday night went with a
more southerly solution this run, with the GFS and ECMWF keeping
the associated precip well south of the NAM solution. Given the
erratic nature of the solutions out of the models at this point,
keeping the slight chc/chc pops across the northern tier for now.
Rain for Monday and Monday night is expected, before briefly
changing over to snow on its departure to the east on Tuesday.
Models are relatively consistent in suggesting that this wave will
shift us back to a busier and more progressive northwesterly flow
pattern aloft. Several waves suggested in this pattern, but the
GFS is pretty robust with the development of a surface ridge,
inhibiting precip development (Wed night in particular). Low
confidence dry forecast through the middle of the week once the
northwesterly flow kicks in. The next major storm is taking shape
going into next weekend, with precip starting on Fri.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 653 PM CDT Sat Mar 17 2018
Low-end MVFR CIGS will sink south of central Illinois this
evening, providing a return to VFR conditions. However, expect at
least MVFR fog to develop across the area later tonight. Once the
fog burns off Sunday morning, VFR are expected. Light winds will
prevail through the 00Z TAF valid time.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Bak
SHORT TERM...HJS
LONG TERM...HJS
AVIATION...Bak
Area Forecast Discussion
National Weather Service Jacksonville FL
902 PM EDT Sat Mar 17 2018
.UPDATE...The Atlantic sea breeze made it to the I-95 corridor and
with the evening cooling and encountering the west wind is eroding
this evening. Surface flow that was disrupted as a result of the sea
breeze will veer back to the southwest late this evening and overnight.
coupled with a weak surface winds, wet soils, and a pocket of
dry air between 850 and 500mb will yield areas of fog across the
region through mid-Sunday morning. SREF and HRRR do hint at patchy
fog developing over the interior portions of SE GA and NE FL
mainly west of highway 301 with lower clouds over the Suwannee
Valley and interior SE GA. Current forecast has these trends and
no updates this evening.
&&
.AVIATION...VFR conditions through much of Tonight. Latest guidance
suggests some low cloudiness and patchy fog could develop after 09z,
and continued this potential for this in latest TAFs til about
12-13z. Would anticipate VFR conditions mid morning onward Sunday
with light westerly surface winds with perhaps a seabreeze at St.
Augustine and Saint Simon`s during the mid to late afternoon.
&&
.MARINE...High pressure will shift S and E of the waters during the
weekend. A series of low pressure systems will track to the north of
the waters. This will maintain a southwesterly flow in the 10-15 kt
range and 2-4 ft seas through the weekend. A stronger system will
approach the waters late Monday and Tuesday resulting in increased
southwest winds and seas as well as potential for scattered showers
and thunderstorms. A strong cold front will move across the waters
Tuesday night. Winds and seas expected to increase to advisor
criteria Tue-Wed.
Rip Currents: Low risk expected with offshore flow through Sunday.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 59 81 60 76 / 10 10 70 60
SSI 60 76 60 71 / 10 10 60 80
JAX 58 81 60 81 / 10 10 40 70
SGJ 57 79 58 78 / 10 10 20 60
GNV 56 82 58 80 / 10 10 20 50
OCF 56 82 58 81 / 10 10 10 40
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&
$$
Cordero/Shuler/McGinnis
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1051 PM EDT Sat Mar 17 2018
.UPDATE...
Issued at 1051 PM EDT SAT MAR 17 2018
The forecast was updated to remove any last mention of
thunderstorms and to account for ongoing rain showers that will be
moving across the eastern third of the forecast area over the next
hour or two. The rest of the forecast was in good shape with the
latest obs used to establish new trends. The night shift will need
to issue one more update early in their shift once the last of the
ongoing rain showers finally exit the area.
UPDATE Issued at 900 PM EDT SAT MAR 17 2018
Now that the severe weather threat has ended across the area, the
severe thunderstorm watch has been cancelled. The forecast and the
hazardous weather outlook products have both been updated to
reflect this changes. Also updated the precipitation forecast for
the rest of tonight based on current radar trends and the latest
run of the HRRR model. Now have thunderstorms moving out of the
area between 2 and 3Z and precipitation overall moving out of
eastern Kentucky between 4 and 5Z. Will need to issue another
update toward the end of the shift to get rid of any remaining
evening wording and for areas where the ongoing precipitation will
have already ended for the night.
UPDATE Issued at 735 PM EDT SAT MAR 17 2018
Have updated the grids with the latest obs to establish new
trends. Will leave the severe thunderstorm watch and zone forecast
text product as is until we cancel the watch this evening after
the severe threat has finally ended. It does appear that the
severe weather threat will end across our area well before the
midnight EDT expiration time of the watch. It also appears that we
may be able to take precipitation out of the area a bit faster
than the inherited forecast has been indicating, but will continue
to monitor current radar trends and the latest model data to
before making that determination.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 520 PM EDT SAT MAR 17 2018
A cold front was bisecting the forecast area from east to west
late this afternoon, with a low pressure system tracking along the
front from central into eastern KY. Showers and thunderstorms have
quickly developed along the front. The regime will shift southward
this evening. There is good speed shear in place, and dry mid
levels with steep lapse rates. The severe weather parameter which
is looking puny is the moisture. Strong heating has mixed drier
air to the surface with dew points only in the 30s and 40s over
most of the southern portion of the area late this afternoon. Can
not rule out severe weather in places where higher dew points
linger or redevelop, but for much of the area late afternoon
conditions don`t look all that favorable. Freezing level and wet
bulb zero height are quite low, which favors large amounts of
small hail. Any large hail would probably need to come from storms
with significant rotation. Storms should taper off from northwest
to southeast this evening after cold fropa.
Surface high pressure passing to our north will provide fair
weather Sunday into Sunday night. Another low pressure system
heading east from the southern plains will pull the front back north
toward KY as a warm Sunday night. Showers could make a return to
our southwest counties by dawn, but will more likely hold off
until the daytime on Monday.
.LONG TERM...(Monday through Saturday)
Issued at 520 PM EDT SAT MAR 17 2018
Model solutions are in decent agreement, sufficient enough to pick
out the main features of concern through the extended. Flow aloft
amplifies with time but remains fairly progressive, with implications
that our generally unsettled pattern will continue with only one
relatively short period of fair weather from Thursday through at
least part of Friday. Consequently our weather is active straight
out of the gate as a mid level low, upper level wave moves into the
region Monday. Additional shortwave disturbances follow Tuesday into
Wednesday before exiting to our east by Thursday. Solutions differ
on timing another shortwave disturbance into the region by the end
of the period, with the 12Z GFS bringing our next weather maker into
the area by late Friday into Saturday. The 0Z ECMWF and 12Z Canadian
hold off on this system until beyond the end of the period, and seem
to suggest a deeper, more organized storm system.
Closer to the surface, a low pressure system will pass through the
Tennessee Valley Region Monday/Monday night. Instability is marginal
but may be enough to kick of a thunderstorm or two late Monday into
Monday night. Shortwave disturbances following in the wake of the
initial low will be responsible for the redevelopment of another
surface low or two over the southern Appalachians through Tuesday
and Wednesday. If enough cold air manages to be drawn southward into
the region from the north, sensible weather may feature a wintry mix
of rain and snow showers for a period of time late Tuesday night
into Wednesday morning, particularly across the higher terrain.
However, details remain a bit too sketchy to provide any specifics
for now. Drier conditions will work into the area by Wednesday night
and Thursday as ridging moves in from the west. Fair weather should
continue through much of Friday before the next potential weather
maker moves in from the west by late week or early into the weekend.
Comparing models favored a slower arrival of the precipitation for
the end of the extended and would not be surprised if Friday winds
up dry in the end. But should not discount the GFS solution totally
based on its recent very good performance with the last few systems
to affect our area. Otherwise, near normal temperatures initially
will cool to well below normal for the mid week time frame. Temps
then rebound for the end of the week and following weekend. |
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
ISSUED AT 735 PM EDT SAT MAR 17 2018
Showers and a number of thunderstorms will continue to move across
eastern Kentucky this evening. Based on the latest upstream radar
trends, it appears that the showers and storms will be ending at
LOZ, SME, and SYM by 1Z or so this evening, by 2 or 3Z at JKL,
and between 4 and 6Z at SJS. Any storms may produce MVFR
conditions at any given airport this evening. It appears that SJS
and JKL will have the best chance of seeing a shower or storm to
begin the TAF period. Will continue to monitor the ongoing showers
and storms and will update the TAFs as necessary as the rain moves
off to our east. Conditions should begin to improve VFR at the
TAF sites between 13 and 17Z on Sunday. Cloud cover should
progress from OVC to BKN to SCT during that time as well, with
clear to mostly clear skies expected by Sunday afternoon.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AR
SHORT TERM...HAL
LONG TERM...RAY
AVIATION...AR
Area Forecast Discussion
National Weather Service Louisville KY
734 PM EDT Sat Mar 17 2018
...Updated Aviation Discussion...
.Mesoscale Update...
Issued at 720 PM EDT Sat Mar 17 2018
Storms have pushed into eastern Kentucky and the air mass over
central Kentucky has stabilized, so our portion of Severe T-storm
Watch 10 has been cancelled. There were a few reports of small hail,
but nothing severe that we are aware of.
The remainder of the night should be dry as we are into northerly
low-level flow and cold advection. Last set of updates was issued a
few min ago.
Issued at 550 PM EDT Sat Mar 17 2018
Convection is already on a downward trend after getting a few sub-
severe reports from Marion County eastward to Lincoln. The main
boundary of concern runs from near Greensburg to Stanford, and that
will be the main focus of any remaining SVR threat. Will start
peeling off the western/northwestern layer of counties from WW 10
this hour, with the rest of central KY likely to come down next
hour.
Issued at 433 PM EST Sat Mar 17 2018
Storms have developed along a well defined surface boundary
stretching across central KY in an environment characterized by 1000-
1500 J/Kg surface based instability coincident with 50-55 knots of
effective bulk shear. Given strong speed shear with height along
with some veering with height, supercell structures (some splitting)
are possible. The main concern is large hail given freezing levels
around 8K feet and -20C heights around 18 K feet. A damaging wind
threat will also exist given steep low level lapse rates with a 20
degree T/Td spread at the surface. There is a possibility that
storms could congeal, and if a cold pool is established the wind
threat would increase.
An isolated tornado can`t be ruled out, however low level surface
winds aren`t overly backed to promote horizontal streamwise
vorticity ingestion. In addition, LCL`s are in the 1000-1200 M
range. Latest mesoanalysis shows effective SRH values around 50-100
M2/S2 along the boundary so there is some localized enhancement of
the environment along the front.
Severe Thunderstorm Watch #10 was just issued and expires at
Midnight EDT. However, expect storms to move east of our area by
around 6-7 PM EDT.
&&
.Short Term...(This evening through Sunday night)
Issued at 215 PM EDT Sat Mar 17 2018
As of 2 PM, a surface analysis showed an area of low pressure
centered near Owensboro, Kentucky. GOES-East mesoscale visible
imagery depicted an arch of enhanced cumulus denoting the warm front
location that was along an Owensboro-Elizabethtown-Lexington line.
South of that boundary, spring-like weather prevailed with mostly
sunny skies, breezy southwest winds, and temperatures in the 70s.
Northward, across southern Indiana, lower clouds and easterly flow
prevailed and readings were in the 40s. Across the forecast area,
there is about a 30-35 degree temperature gradient.
A pool of near-60 degree dewpoints lie across south-central
Kentucky, contributing to about 500 to 1000 J/kg of surface-based
CAPE, per recent RAP mesoanalysis and GOES-East CAPE derived
product. Aloft, the presence of a passing shortwave is providing
modest deep-layer shear, on the order of 40 to 50 kts.
In the next 3-5 hours, a brief window of opportunity exists for
strong to marginally severe thunderstorms where the axis of
instability remains as the surface low tracks east through central
Kentucky providing the necessary lift to initiate convection. The
available hi-res models show the area where the risk exists is from
around Lexington southward toward Lake Cumberland, and as far west
as Glasgow, Campbellsville, and Springfield Kentucky. The latest SPC
Day 1 outlook nudged the marginal/slight risks westward from the
early morning issuance.
The main hazards for any storm that does develop is large hail
(quarter sized) thanks to the lower freezing levels (8-10 kft),
steep low-level lapse rates, and drier air aloft. If storms
organized into small clusters, a damaging wind threat also exists.
The main time frame is from around 3-4 pm through 7 pm as the storms
develop and quickly move eastward into eastern KY/TN.
The surface low moves east of the area this evening and drags the
cold front back through the area. There is a drizzle / light shower
chance across the northern areas and northern Bluegrass later this
evening, then temperatures tonight will fall into the upper 30s to
lower 40s with mostly cloudy to overcast skies.
On Sunday, seasonable readings are expected as high pressure builds
into the region. Drier air working in from north will erode the
cloud layer initially over southern Indiana and north central
Kentucky, where a mostly to partly sunny day is expected. Further to
the southwest, across south-central and west-central Kentucky, the
effects of that dry air are limited and time-height cross sections
show more moisture lingering, so a mostly cloudy to overcast day is
forecast. The clouds will impact high temperatures, and southern
Indiana may end up slightly warmer than south-central Kentucky by a
few degrees. Most areas will range from 55 to 60.
The next weather system is quick to move into the region as the
upper level pattern remains quite progressive. Showers are likely
Sunday night, especially after midnight across south central and
central Kentucky. Lows will fall into the 40s.
.Long Term...(Monday through Saturday)
Issued at 220 PM EDT Sat Mar 17 2018
An unsettled weather pattern is in store for the upcoming work week
across the lower Ohio and Tennessee Valleys. The progressive but
active pattern could bring both spring and winter weather to the
area.
The 17.12z models are in reasonable agreement showing a compact
shortwave tracking across the Tennessee Valley Monday. At the
surface, a low pressure looks to organize and track across middle TN
during the afternoon and evening hours. This setup will put a warm
front somewhere along the KY/TN border or into south-central KY. The
best dewpoint surge, instability, and potential severe weather
threat continues to be across TN/AL/GA. However, a time-trend
analysis over the last several model runs shows a slight northward
jog in the surface low and shortwave, and if this trend continues,
portions of south-central KY could be under a threat for stronger to
severe storms Monday afternoon/evening.
Further north, a frontogenetical band of rain is likely to setup
across southern Indiana and north central Kentucky. As temperatures
cool behind the front Monday night and Tuesday morning, a brief
changeover to wet snow is possible but at this time, the colder air
lags the precipitation enough to preclude much if any snowfall
accumulation.
The Tuesday-Wednesday period has more uncertainty and lower
confidence. The potential phasing or not of the upper level energy
and the southern stream system could spread light precipitation
across portions of eastern and central Kentucky. It does appear to
be much colder with highs in the 40s, and potentially staying stuck
in the 30s. For now, continued with a model consensus but will need
to watch this period for the potential for light snow accumulations
across the Bluegrass.
The remainder of the work week looks more benign with high pressure
and seasonably cool temperatures. Toward next weekend it appears
another system may track through the Midwest and OH Valleys and
bring chances for showers and thunderstorms to the area.
&&
.Aviation...(00Z TAF Issuance)
Issued at 733 PM EDT Sat Mar 17 2018
Scattered storms have now pushed east of the region, with the
frontal boundary that they initiated on also sinking south of the
TAF sites. Therefore, we`ll stay dry the rest of this forecast
cycle, with steady NW winds slackening and becoming light and
variable later tonight. The biggest concern will be low ceilings
already working into the region from the north, and expected to
persist for much of the overnight. Have the TAFs mostly going into
the low MVFR range below fuel-alternate, but can`t rule out some
brief IFR at HNB or LEX around Midnight into the pre-dawn hours.
Covered this potential with a TEMPO. Ceilings should improve close
to sunrise at SDF/LEX/HNB, but expect them to persist at BWG well
into the afternoon on Sunday.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...None.
&&
$$
Mesoscale...BJS/RAS
Short Term...ZT
Long Term...ZT
Aviation...BJS
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1044 PM EDT Sat Mar 17 2018
.SYNOPSIS...
A warm front lingering across the area will push southward as a
cold front tonight and early Sunday morning. A strong area of
low pressure will affect the area Monday night and Tuesday. High
pressure will build in from the northwest late next week.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
As of 1030 PM Sat...High pressure remains centered off the SE
coast with a frontal boundary bisecting the region, roughly
from Ocracoke to across the Pamlico River. Convection becoming
enhanced across north-central NC along the sfc front as upper
level dynamics improve with an approaching shortwave trough.
SPC has lowered the severe risk to marginal across the area for
the overnight as the MCS moves into the region. The primary
severe threat remains to be for damaging wind gusts and large
hail. The sfc front will slowly push S across the CWA overnight
with only far southern areas remaining in the warm sector as
the convection moves across the area. Latest update from the
HRRR shows the convection entering NW portions of the CWA around
1 am and pushing off the coast around 6 am with greatest
coverage across northern areas. Temps will remain mild south of
the front, generally in the 50s to lower 60s but will cool into
the 40s after the front pushes through and southern area will
likely not drop into the 40s until late tonight.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
As of 3 PM Sat...The cold front will continue to push through
the southern areas early Sunday morning, as low pressure and
shortwave push further offshore. Could still see some lingering
showers along the coast early, but that should taper off Sunday
morning with skies becoming mostly sunny from north to south.
Low level thickness values and N/NE flow support highs 50-55
degrees across the NE counties and 55-60 degrees across the SW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
As of 330 AM Saturday...A strengthening closed mid- level low
will lead to rapid strengthening of a surface low that will move
across Tennessee and intensify off the NC coast early Tuesday
at about 995 mb. Widespread showers will enter the region Monday
afternoon with the heaviest precipitation Monday night. With
strong low-level wind fields and backed SE flow, there would be
some concern for strong storms, but instability appears to be
limited to offshore areas at this time and will continue to
carry showers. A unsettled pattern looks to continue Wednesday
into Thursday as deep moisture swings through the area with deep
mid-level trough and strong shortwave energy. Thermal profiles
from both the GFS and ECMWF continue to support a rain/snow mix
Wednesday night with light rain possible Thursday. Have PoPs in
the slight chance to low chance range at this time, but with
models showing a bit better agreement, may be to raise those
PoPs on later updates. Drier air returns Friday with weak
surface ridge building in from the northwest. Temperatures will
show wide variation through the extended period with highs well
into the 70s Tuesday in the S/SW flow ahead of the strong low,
dropping into the lower 30s by Thursday morning behind the low
with the possible light rain/snow mix.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
Short Term /through Sunday/...
As of 8 PM Sat...Pred VFR expected this evening with light SW
winds at the terminals. After midnight through roughly 6 AM,
the models continue to indicate the potential for organized
strong convection and sub VFR conditions moving east along a
southward moving cold front which is currently stalled across
the northeastern portion of Eastern NC. The front will move
south of the area late tonight with a period of IFR ceilings
expected in the northerly post frontal flow from 6 AM through 11
AM with conditions improving to VFR around 2 PM Sunday as drier
air filters into the area.
Long Term /Sunday through Thursday/...
As of 145 PM Saturday...High pressure will bring drier air and
VFR conditions from Sunday afternoon through about midday
Monday. Deep moisture associated with the next system will lead
to widespread showers Monday night and Tuesday with MVFR/IFR
conditions expected along with gusty SW/W winds. With lingering
precipitation associated with a strong upper-level feature, some
MVFR ceilings with showers are possible into Wednesday, then
VFR conditions prevail on Thu as high pressure begins to build
into the area.
&&
.MARINE...
Short Term /through Sunday/...
As of 9 PM Sat...A front continues to bisect the waters and latest
obs show SW winds 15-25 kt with gusts as high as 30 kt south of
Cape Hatteras, and E/NE 5-15 kt north. Seas continue around 2-4
ft north but have built to 4-7 ft to the south where stronger
winds have occurred this evening. The front will push southward
overnight and is progged to be across the far southern waters
late tonight with N/NE winds becoming 10-15 kt behind the front.
NNE surge 15-25 kt will develop behind the front Sunday.
Seas expected to subside to 2-5 ft late tonight but build back
to 3-6 ft Sunday with the N/NE surge. Continue SCA for the
waters south of Oregon Inlet and Pamlico Sound into Sunday.
Long Term /Sunday night through Thursday/...
As of 330 AM Saturday...N winds at 15-20 knots initially on
Sunday will become E/NE 5-15 knots Sunday night through Monday
with seas subsiding from 3-5 feet to 2-3 feet Monday as weak
high pressure settles over the waters. By Monday night, SE winds
increase to 15-20 knots with seas building to 4-6 feet. Winds
will veer to SW then W Tuesday into Wednesday with seas building
to as high as 9 feet in the central waters by Wednesday
morning.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...Small Craft Advisory until 8 PM EDT Sunday for AMZ152-154.
Small Craft Advisory until 5 PM EDT Sunday for AMZ156-158.
Small Craft Advisory from 6 AM to 5 PM EDT Sunday for AMZ135.
&&
$$
SYNOPSIS...CQD
NEAR TERM...SK/CQD
SHORT TERM...CQD
LONG TERM...CTC
AVIATION...CTC/SK
MARINE...CTC/SK/CQD
Area Forecast Discussion...UPDATED
National Weather Service Mobile AL
1002 PM CDT Sat Mar 17 2018
.DISCUSSION...See updated information for land areas below.
&&
.UPDATE...The earlier scattered convection over our region has
come to an end, with our local radars now back in clear air VCPs
as of 945 PM. We have updated the forecast to remove POPs for the
rest of the evening. The next upstream shortwave trough will be
approaching the Lower Mississippi Valley overnight. High resolution
guidance and most of the deterministic model guidance are in
agreement that most of the ascent with this next feature will remain
to our west through 12Z, though there is some indication that
isolated light showers could develop over our western zones late, so
will leave only 20 percent POPs in place across this portion of the
area during the overnight hours. The main impact overnight looks to
be development of patchy to areas of fog, especially south of the
U.S. Highway 84 corridor, where the NAM-12, RAP, and HRRR are all
indicating development overnight, not to mention >60% SREF
probabilities of visibility less than 1 mile. We have included areas
of fog vs. patchy over the central and southern zones in the latest
update (keeping patchy mention for now in the north). The overnight
shift will monitor observations closely for dense fog development.
All other forecast elements look on track. /21
&&
.PREV DISCUSSION... /issued 623 PM CDT Sat Mar 17 2018/
DISCUSSION...Updated for latest aviation discussion below.
AVIATION...
00Z issuance...Expecting mostly VFR conditions this evening with
some MVFR ceilings possible from convective blow off clouds to the
west of Mobile. As showers and storms come to an end this evening
we should see a general increase in ceiling height through about
midnight or so. Thereafter ceilings will lower as low stratus and
fog are possible through early morning. Chances for showers and
storms will increase as we head through the morning hours. 05/RR
PREV DISCUSSION... /issued 420 PM CDT Sat Mar 17 2018/
NEAR TERM /Now Through Sunday/...A cold front will move into the
Tennessee Valley this evening then slowly sink southward and stall
across south central Mississippi and Alabama on Sunday. South of the
this front, a very moist airmass will remain in the place with
dewpoints in the mid 60s. This afternoon daytime heating is
generating scattered showers and isolated thunderstorms across
portions of the area. These will continue through early evening
before dissipating tonight as the boundary layer cools. Although an
isolated shower is possible overnight, most areas will remain dry.
The increased moisture and light winds will allow for at least
patchy dense fog to develop late tonight into Sunday morning. Lows
tonight fall into the low 60s inland to mid 60s along the coast.
A shortwave is expected to generate showers and storms across
eastern Texas this evening which may congeal into an MCS and move
eastward along the stalled front overnight. Depending on how well
developed the convection becomes, it could act to enhance
thunderstorm development on Sunday. Meanwhile, the airmass along and
south of the stalled front is expected to become moderately unstable
by tomorrow afternoon with MLCAPE values around 1000 J/Kg. In
addition strong deep layer shear of 50 to 60 knots is expected. As a
result, any cells that develop near or just south of the boundary
will be capable of becoming severe with damaging winds and large
hail. An isolated tornado is also possible due to the enhanced shear
near the front. This is where the Storm Prediction Center has
outlined a slight risk of severe storms, roughly north and west of a
line from Leakesville to Evergreen to Greenville. /13
SHORT TERM /Sunday night Through Tuesday night/...An upper level
shortwave over the Great Plains pushes east into the Mississippi
River Valley Sunday night into Monday morning. Ahead of this
system, onshore flow will continue to pump Gulf moisture into
local area and convection will likely be ongoing along and south
of a quasi-stationary front draped across the Mid South. Despite
the loss of diabatic heating after sunset, an EML overspreading
the region from the west will maintain at least a modest amount of
elevated instability throughout the night, with MUCAPE remaining
around 1500 J/kg per latest guidance. Thus, expect storms to
continue during the overnight hours Sunday night into Monday.
Effective bulk shear around 50 knots and mid-level lapse rates
increasing to around 7.0 C/km (courtesy the aforementioned EML)
will support the chance for some strong to possibly severe
thunderstorms capable of producing large hail and gusty straight-
line winds.
The ingredients for strong to severe storms linger throughout the
day Monday as the upper trough and attendant surface low continue
to push east into the Tennessee Valley. The return of daytime
heating results in further destabilization of the warm sector,
with guidance continuing to suggest upwards of 2500 J/kg SBCAPE
developing during afternoon hours. Strengthening 850 mb flow
supports effective bulk shear values around 50 knots, meaning
storms that are able to form will have the chance to organize and
become strong to severe. However, there is some uncertainty
regarding convective initiation Monday afternoon, as some high-
res guidance suggests warm 850 mb temperatures maintaining a
capping inversion over our area through much of the day, and the
best forcing to overcome this cap would stay primarily to our
north in closer proximity to the surface low and upper shortwave.
Due to this uncertainty, have kept the best chances for strong to
severe thunderstorms on Monday over the northeastern portion of
the local area, where the best forcing will likely be realized
before the cold front eventually sweeps through. There is a
marginal risk across the remainder of the area, as any storms that
are able to form will be capable of organizing and becoming
strong to severe as well. The primary threats will be large hail
and damaging straight-line winds. Please see the Storm Prediction
Center website (www.spc.noaa.gov) or our homepage
(www.weather.gov/mob) for the latest information regarding severe
weather potential Sunday night and Monday.
The cold front passes through Tuesday morning, effectively ending
rain chances and ushering in cool and dry air to finish off the
short term period. Tuesday night lows will be much cooler as a
result, dipping into the low 40s across the area. /49
LONG TERM /Wednesday Through Saturday/...A deepening upper
longwave trough over the eastern CONUS pushes east over the
Atlantic Ocean through the long term, with dry deep-layer
northwest flow setting up over the local area as an upper ridge
builds to our west. Will see cool and dry conditions beneath
mostly clear skies Wednesday through the remainder of the week as
a result. Highs reach the mid and upper 60s each day and lows dip
into the upper 30s to low 40s each night. /49
MARINE...A predominantly light to occasionally moderate south to
southwest flow is expected to continue over the coastal waters
through Monday as Atlantic high pressure continues to ridge west
across the eastern Gulf and a frontal boundary remains nearly
stationary well to the north of the marine area. A stronger cold
front approaches the marine area Monday night and is expected to
move east across the coastal waters Tuesday with winds shifting to
the northwest and increasing, along with building seas. /13
&&
.MOB WATCHES/WARNINGS/ADVISORIES...
AL...None.
FL...None.
MS...None.
GM...None.
&&
$$
This product is also available on the web at:
http://weather.gov/mob
Area Forecast Discussion
National Weather Service Phoenix AZ
817 PM MST Sat Mar 17 2018
.SYNOPSIS...
The approach and passage of a weather system will lead to breezy
to windy conditions over much of the region today and tonight as
well as a chance of showers...mainly east of the Lower Colorado
River Valley. There will be some cooling as well with highs in
the 60s on Sunday. Below normal temperatures through Monday should
warm back into the 80s for the middle of next week. Another
weather system will provide an opportunity for rain and cooler
temperatures late next week.
&&
.DISCUSSION...
Upper level low tracking into the Southwest this evening,
currently making its way across the Sierra Nevada. Ahead of it,
nice little baroclinic leaf developing. Unfortunately the
inflection point is near the Grand Canyon and well north of our
forecast area. In general, the system seems to be under-performing.
Winds are not quite as strong as anticipated and appears most of
the lifting will be further north. HRRR for most of the afternoon
and evening has been underwhelming showing scant precipitation and
weaker wind fields. Adjusted pops down just a bit but still a
chance for some light rain (this was never going to be a big
producer, more the higher pop/low qpf scenario).
Will continue the WI.Y across far southwest Imperial County. Winds
have been in a bit of a lull there but are showing some increasing
trends.
For the early to middle portion of next week, high pressure aloft
will build back over the desert southwest allowing for dry
conditions and a sharp warming trend. High temperatures will climb
back into the mid to upper 70s by next Tuesday and then into the
middle 80s over the warmer deserts next Wednesday. We will see
periods of mainly high clouds spreading through the ridge
resulting in partly to mostly cloudy skies Tuesday into Wednesday,
but the high cloud cover will not keep temperatures from reaching
into the 80s.
For the latter part of next work week - Thursday into Friday -
operational GFS and ECMWF as well as GEFS ensembles continue to
paint a picture that suggests another Pacific low will move inland
and across the area, bringing another chance of showers to the lower
deserts. Confidence in exact timing is low still, but somewhere in
the Thursday/Thursday night time frame seems like the best bet for
rain in the greater Phoenix area. NAEFS POP trend still looks to be
decent with numbers that are a bit overdone but not too much. Expect
quite a bit of cloud cover along with temperatures cooling back into
the 70s with the passage of this next system.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Latest trends and guidance are looking less impressive with this
system. Winds speeds have been paired back a bit and the TEMPO of
ceilings around 5kft was removed. Still a chance the ceilings
materialize in the 10-13Z window but not confident enough anymore
to carry in the TAF.
Southeast California/Southwest Arizona including KIPL and KBLH:
Gusty westerly winds will continue this evening then slacken
overnight. Little indication of significant dust at this time
though always a potential with higher winds. Area METARs reporting
clouds/cigs in the 7-8kft range and they should remain there for a
few more hours before decreasing behind the passing front. Lighter
winds with few clouds Sunday.
Aviation Discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Monday through Friday...
Very dry conditions together with a warming trend across the
region will predominate through Wednesday. A weather system on
Thursday will bring a chance of light rain from SE CA to AZ.
Seasonably warm daytime temperatures early in the weak will
increase to the mid 80s by Wednesday and then drop back down into
the upper 70s on Thursday. Min RH`s in the 8-15% range through
Wednesday are expected to jump up to the 20-25% with Thursday`s
system. Very breezy to windy southwesterly winds gusting to
20-25kt from SE CA to SW AZ will also accompany the system on
Thursday. Generally fair overnight recoveries should improve to
fair to good by Thursday.
&&
.SPOTTER INFORMATION STATEMENT...
Spotters should follow standard reporting procedures.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...Wind Advisory until 5 AM PDT Sunday for CAZ562.
&&
$$
DISCUSSION...Iniguez/CB
AVIATION...Iniguez
FIRE WEATHER...Sawtelle
Area Forecast Discussion
National Weather Service San Angelo TX
704 PM CDT Sat Mar 17 2018
.UPDATE...
We have cleared our counties from the severe thunderstorm watch.
With the loss of daytime heating, the atmosphere is becoming more
stable. Will keep a slight chance of showers and storms in the
grids until midnight, with a few lingering showers between
Ballinger and southern Taylor county.
08
&&
.PREV DISCUSSION... /issued 637 PM CDT Sat Mar 17 2018/
UPDATE...
A few strong storms lingering across the eastern counties with one
severe storm currently exiting San Saba County. Will keep the
thunderstorm watch going a little bit longer, but expect the
remainder of the storms to weaken as we head toward sunset.
08
AVIATION...
/00Z TAFS/
VFR expected for the next 24 hours. Main concern for TAFS will be
stronger winds tomorrow. Thunderstorms have moved east of TAF
locations this evening, so expecting VFR to continue. Will see
winds weaken after sunset mainly southeast overnight. Dryline and
Pacific front early Sunday will shift winds to the west to
northwest with gusts of 30 to 35 kt possible.
08
PREV DISCUSSION... /issued 325 PM CDT Sat Mar 17 2018/
SHORT TERM...
(Tonight and Sunday)
Complicated surface pattern this afternoon with the stationary
frontal boundary south of the Big Country, with a dryline
extending south across the Hill Country. As the back edge of the
mid and high clouds exited, temperatures and instability climbed
and convection developed. Storms should end before 00Z and take
most of the precip with it.
High res models such as TTU WRF and the HRRR show an fast morning
area of high based showers moving across the area late tonight
into Sunday morning, with global models showing drier conditions.
Not really accounted for in the forecast at this point, and will
not add at this point, but will need to be watched to see if a
little light rain will need to be added to the forecast for late
tonight.
Critical fire weather conditions still the main problem for Sunday
and Monday, as gusty west and northwest winds develop behind a
dryline and pacific front. Temperatures will soar behind the
dryline with strong downslope flow, with readings near 90 in some
locations.
LONG TERM...
(Sunday Night through Friday)
As mentioned, fire weather the main concern for Monday in the wake
of the cold front. Temperatures will be cooler, with highs in the
60s and 70s. Dry air mass will allow for some decent radiational
cooling Monday night, with lows around 40. Gradual warmup for
the remainder of the week
FIRE WEATHER...
Critical fire weather conditions the main forecast concern. With a
lack of recent rainfall, ERC values are starting to climb across
the area. Winds will shift to the west and start to increase
behind the dryline on Sunday afternoon, but highest winds will
wait until late afternoon as the pacific front moves into the
area. With humidity values falling into the 10 to 15 percent
range, west winds of 20 to 25 mph at the 20 foot level will create
dangerous fire weather conditions mainly west of an Abilene to San
Angelo to Ozona line.
Wind speeds will continue Sunday Night, and humidity recovery will
be very slow. Max humidity values Sunday Night will only reach
into the 30 to 40 percent range for many locations. As as get into
the day Monday, wind speeds will continue to be high and humidity
values will quickly drop below 20 percent as temperatures begin to
climb. Will be cooler on Monday than we see on Sunday, but
critical fire weather conditions will still develop. A Fire
Weather Watch has been issued for all of West Central Texas. Wind
speeds will finally begin to ease and humidity values increase by
early Monday evening.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 55 85 49 69 / 10 10 0 0
San Angelo 57 87 47 74 / 10 10 0 0
Junction 57 89 46 77 / 20 10 5 0
Brownwood 56 87 47 73 / 20 20 0 0
Sweetwater 55 83 47 69 / 10 10 0 0
Ozona 56 86 46 71 / 10 10 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from noon to 9 PM CDT Sunday for Coke-Crockett-
Fisher-Haskell-Irion-Jones-Nolan-Runnels-Sterling-Taylor-Tom
Green.
Fire Weather Watch from Monday morning through Monday evening
for Brown-Callahan-Coke-Coleman-Concho-Crockett-Fisher-Haskell-
Irion-Jones-Kimble-Mason-McCulloch-Menard-Nolan-Runnels-San Saba-
Schleicher-Shackelford-Sterling-Sutton-Taylor-Throckmorton-Tom
Green.
&&
$$
99/99
...Update to aviation forecast discussion...
.SHORT TERM...(This evening through Sunday)
Issued at 300 PM CDT Sat Mar 17 2018
An upper-level ridge is currently progressing across the Central
Plains with a surface high pressure centered in SD and IA. Residual
moisture in the form of stratus is present over northeast KS.
Diurnal mixing on the southwest periphery of the stratus is slowly
eroding the clouds towards the northeast. These clouds along with
light northerly winds is keeping the temperatures in the upper 40s
to mid 50s. The surface ridge orientated north to south slides
through the area today and tonight keeping winds light and gradually
veering overnight. Areas that receive minimal heating this
afternoon but clear out this evening could have enough radiational
cooling to support fog towards sunrise.
The next midlevel low tracks over CO and NM tomorrow forcing a
northward moisture flux. The surface front is currently over
northern TX so modification of the post frontal air mass in OK
and KS will be difficult given the short amount of time before the
systems arrives. A more modest moisture transport appears to
occur around the 800-700 mb layer beneath a modest EML. This
moisture should be in place once the lift increases Sunday evening
and contribute to marginal elevated instability. A narrow
corridor of surface dew points in the upper 40s advects northward
ahead of the surface cyclone into central and southwest KS by
Sunday afternoon. It appears convection could initiate in the
vicinity of the surface cyclone and then weaken as it progresses
eastward given the narrow zone of positive buoyancy. Therefore
only expected some embedded thunder within the large scale
precipitation shield that is forecasted to move through portions
of eastern KS.
.LONG TERM...(Sunday night through Saturday)
Issued at 300 PM CDT Sat Mar 17 2018
There is still slight discrepancy regarding the track of the
midlevel low pressure Sunday night. The overall consensus is for
the low to pass over the OK/KS state line, which places the upper-
level divergence and PVA along and south of I-70 Sunday night
into Monday morning. The expected rainfall will also be partially
dictated by the northward extent of the moisture advection. The
GEFS shows more spread in the QPF especially for northern KS,
which is likely due to the southward shift and track discrepancy.
This has caused a southward shift in the heaviest axis of rainfall
and an overall reduction in forecasted QPF for the area.
Another weaker shortwave ejects out of the Rockies over SD/NE Monday
night into Tuesday. This may support additional precipitation mainly
along and north of I-70 Monday night. Cooler temperatures advecting
southward and the lack of diurnal heating may support a rain-snow
mix. The QPF expected during this time frame is fairly minor so do
not expect many impacts at this point. The series of shortwave
troughs tracking over the Northern Plains and Upper Midwest
eventually deepen the longwave trough over the eastern US. This
keeps our region in the northwest flow aloft until Thursday. An
approaching shortwave trough embedded within the southwest flow
aloft will drive warm air advection precipitation across the
region starting Thursday night into Friday. The strength, track,
and timing of this shortwave is not certain, but it could support
a surface cyclone in the region. Temperatures will moderate
through out the week with highs in the 60s and 70s and lows in the
40s by Friday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 629 PM CDT Sat Mar 17 2018
Difficult forecast with MVFR cloud clearing line recently
stalling in TOP/FOE vicinity. HRRR and RAP seem to have the best
handle on this shallow cloud, but still vary notably in its
evolution. At this point have kept it a few more hours but
northeast winds at cloud level could easily keep a BKN deck in
place much of the first half of this forecast. Will also need to
watch BR/FG potential with light winds and crossover temps
expected to be reached, with more concern at MHK, but at this
point expect enough mixing to keep limiting BR in check.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Sanders
LONG TERM...Sanders
AVIATION...65
Area Forecast Discussion
National Weather Service Tucson AZ
831 PM MST Sat Mar 17 2018
.SYNOPSIS...A weather system will bring a chance of valley rain
and mountain snow late tonight into Sunday morning. Expect cooler
temperatures Sunday and Sunday night before high pressure brings
a warming trend the first half of the new week. Another system
will brush by mainly north of the area later in the week.
&&
.DISCUSSION...Shortwave trough axis is now located across central
California with the associated cold frontal band now just pushing
into Arizona across the lower Colorado River Valley. Latest IR
satellite shows mostly clear skies from Tucson westward with some
residual cirroform cloudiness east of Tucson. There is not a lot of
cloud coverage with the cold front upstream of our area near Yuma
but as the front pushes to the east it will pickup a bit of Gulf of
California moisture. This moisture combined with weak forcing and
ascent with the front are expected to result in a few showers on
Sunday morning. Latest HRRR runs and 00Z NAM are certainly not too
excited about shower coverage Sunday morning with the HRRR
consistently not depicting much of anything. Will not make any
changes to the forecast at this time, but if anything our PoPs might
be a touch too high. Bottom line is this is really a minor system
with precipitation amounts generally under 0.05" in the valleys with
slightly higher amounts in the mountains. Just made some minor
changes to tweak for latest trends in sky cover overnight, otherwise
the previous forecast remains unchanged.
&&
.AVIATION...Valid through 19/06Z.
Approaching trough will result in increasing cloud cover late
tonight along with VCSH around KTUS Sunday morning. Looks like best
chance of rain will be centered on 14Z plus/minus a few hours, with
showers exiting the region before 18Z. Any rain that occurs at KTUS
will be light with no restrictions to vsby and only a brief drop in
cigs to around 8kft. KOLS/KDUG likely too far south to see any rain
but will likely see an increase in clouds. Expect southwest winds
around 10-15 kts to become westerly Sunday with afternoon gusts of
20-25 kts possible mainly east of KTUS.
Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Isolated showers expected late tonight into Sunday
morning but any rain/snow will be light. Mostly clear skies and dry
weather are expected from Sunday night through mid/late week.
Another trough will approach the region on Thursday bringing the
next opportunity for rain to the area. As for winds, expect the
strongest winds of the week to be the rest of today into early
Sunday morning. Afternoon breeziness is expected each day Monday
through Wednesday with typical diurnal patterns expected. Gusty
southwest winds should return next Thursday and Friday.
&&
.PREV DISCUSSION...Winds picking up this afternoon ahead of a storm
system digging into the region from the northwest (below advisory
levels but gusty). Most of the action will be north of our area with
this system as it pushes across the region over the next 36 hours.
The associated cold front currently near far western Arizona looks
just a tad slower, and should push across SE AZ between 3AM and
early afternoon. Some upslope and moisture increase ahead of the
front, with a few orographically assisted light showers developing
overnight. Our best rain chances will be immediately ahead of and
with the front, which times out to between 5AM and 9AM MST for
Tucson Metro. With little dynamics and a relatively poor moisture
pool this far from the main system, storm totals will be on the
light side. Say around .05 in valleys and 1/3 of an inch in
mountains. Snow levels falling to around 5500-6000 feet behind the
front with 1 to 3 inches of snow expected in the mountains.
Solid cooling behind the system with daytime highs down 10 or 12
degrees tomorrow, and overnight lows dropping to around 5 to 8
degrees below average for mid March early on Monday morning. That
means mid to upper 30s around Tucson, and mid 20s to lower 30s in
colder valleys east and south of Tucson. Those colder valleys
typically aren`t done freezing yet, and this year is no exception
with a freeze just a few days ago (average last freezes in April for
Santa Cruz, Cochise and Graham counties).
Strong high pressure the first half of the new week. Temperatures
will jump quickly back to 8-10 degrees above average by Wednesday.
Basically some flavor of 80s just about everywhere.
It looks like the storm track is going to have difficulty digging
back into our neck of the woods, so a system pushing across western
states the second half of the new week will probably remain north of
our area. A glancing blow with gusty winds and some cooling, but
best precip chances should be north of us. A common theme even in
early portions of our transition season. We`ll see if we can get any
moisture help off the Pacific, but trajectories aren`t as favorable
this far south.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
$$
Lader/Meyer/Leins
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