Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/29/19
Area Forecast Discussion
National Weather Service Caribou ME
1121 PM EDT Thu Mar 28 2019
.SYNOPSIS...
A cold front will cross the area Friday and stall in the Gulf
of Maine Friday night. Low pressure from the Great Lakes region
will approach the region Saturday then track just north of Maine
on Sunday. A cold front brings sharply colder temperatures
Monday.
&&
.NEAR TERM /THROUGH FRIDAY/...
1110 PM Update...
Tweaked the precip chances per the latest radar which showed an
area of precip in the form of rain and snow moving across the
central and downeast areas. Snow being reported in Houlton(HUL)
as temps dropped back as precip picked up and the column cooled
down. The latest run of the HRRR and Hi Res NNM lining up nicely
w/this area of precip. This set of guidance showed precip
expanding further n overnight as the warm front lifts n and a
decent area of mid level forcing sets up. Stayed close to the
daycrew`s thinking of up to one of wet snow accum possible in
the area of heavier returns across the northern areas such as
Houlton and Millinocket. Temps will level off overnight and then
begin to rise after sunrise. Adjusted hrly temps to fit w/the
last 3hr trends showing the slight cooldown w/the precip, but
stayed close to the current overnight forecast mins given that
temps should level off later on.
Previous Discussion...
Precipitation with the cold front will not be uniform. In fact,
a corridor from southern Penobscot towards northern Washington
and southern Aroostook counties has been consistently identified
by guidance for steadier and possibly substantial amounts of
precipitation totaling over a half inch...possibly up to three-
quarter of an inch. In this area, pops were elevated to
categorical and overall QPF may need to be increased. P-type is
tricky. Today`s warm boundary layer will be cooled as precip
starts to fall and mixing with snow is expected at times as an
isothermal layer around 0C develops from the sfc to H850.
However, warm advection continues up to H850 through the night
ahead of the cold front. As a result, will keep mention of
accumulations to an inch or less in northern zones. The front
will slowly meander southward though Friday...reaching the coast
by evening. Precipitation...mostly in the form of rain...will
continue in the southern half of the forecast area Friday
morning. The front will be accompanied by a lot of moisture up
to H700...resulting in overcast skies through the day across the
entire forecast area. These clouds and the precip led to lower
highs than advertised by some guidance, but also higher dew
points that will promote more snow melt.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
A high pressure ridge will be extended across Maine at the start
of the period. A deepening low southern Mo with its associated
frontal system will move northeast overnight Friday. By
Saturday morning the warm front will extend into SW Me. The warm
front will continue to spread northeast into Northern ME around
mid day Saturday. The GFS/ECMWF/GEM/NAM all show multiple lows
along the cold frontal boundary that extends southwest from the
lead low near Lake Ontario, to east TX. The lows moving along
the boundary will keep the frontal boundary stationary across
the Crown of Maine through early Sunday morning. The 500 HPA
trough will move into western Maine early Sunday morning and
start slowly moving the front to the southeast. By the end of
the period the front will be across central Washington County.
Loaded a blend of the GFS/NAM/ECMWF/GEM to smooth out the minor
differences in the models. Used NWPSCG1CAR for seas in the
coastal waters. Used Wind gust by factor through 12z added 15
kts to wnds for gusts, used GYX Wnd Gust tool for Gust for the
remainder of short term. Used GFS for QPF.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
A cold frontal system will be exiting Maine at the start of the
period. A few lingering showers across Northern Maine,
otherwise higher pressure will build into the area early, and
will dominate through Tuesday afternoon. The high will build
east of the area Tuesday, but its ridge will remain extended
down the Eastern Seaboard. A Deepening low will be tracking
north along the Gulf Stream it will be East of Virginia Tuesday
evening. The guidance disagrees on the movement of this low, the
GFS deepens it and move it into the Bay of Fundy Wednesday
evening, The EC/GEM also deepen it but keeps it well south of
Nova Scotia, with the EC solution being the average of the
GFS/EC/GEM. The EC/GEM solution maintains the ridge across the
region through the end of the period. The GFS moves the low
through the Bay of Fundy into the Gulf of St Lawrence by the end
of the period.
Loaded a blend to smooth out the differences in the models,
however the solution leans more towards the ECMWF solution. Used
NAWAVE4 for seas in the coastal waters. Used windgust by factor
tool.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: VFR conditions will gradually deteriorate
tonight...first to MVFR cigs and towards IFR after midnight into
Friday morning. There is a chance of tempo IFR vis in snow north
of HUL and GNR tonight into early Friday morning. LLWS is
possible north of CAR this evening. Cigs will lift towards VFR
by later Friday as a slow-moving cold front exits the area.
SHORT TERM: VFR with increasing high clouds as a warm front
moves towards the area. MVFR conditions late morning Saturday as
the warm front moves across the state. MVFR to occasionally IFR
in rain and mist across Northern Maine sites, FVE, CAR, PQI,
and HUL spreading to BHB and BGR early Sunday morning as the
Front begins to move southeast as a cold front precipitation
changing to showers. MVFR to occasionally IFR conditions will
continue until early Monday morning when the cold front finally
pushes southeast of the area. Higher pressure will build in
behind the front, clearing conditions with all sites returning
to VFR. A few snow showers across the crown of Maine Monday
night otherwise high pressure will dominate through the end of
the period.
&&
.MARINE...
NEAR TERM: The Small Craft Advisory will remain in effect
through tonight into early Friday morning. Winds and seas will
gradually decrease during Friday.
SHORT TERM: Higher pressure builds into the coastal waters at
the start of the period. Winds and seas below SCA criteria. The
higher pressure system will rapidly track southeast of the area
as a new frontal system approaches from the SW. Winds and seas
will build on Saturday a SCA maybe require Saturday afternoon to
Sunday evening. The frontal system will clear the area Sunday
evening and higher pressure will build in late on Sunday. High
pressure will dominate through the end of the period.
&&
.HYDROLOGY...
Warmer temperatures today through Sunday and rainfall amounts of
a half inch to three-quarters of an inch by Sunday evening
raises the threat of ice breakup by later Sunday into Monday.
The primary threat area appears to be Piscataquis County where
the Piscataquis and Pleasant Rivers appear to be largely ice-
covered based on Sentinel polar-orbiter imagery. There is some
threat in south-central Penobscot into southern Aroostook too,
but there`s generally less ice coverage and snowpack in
comparison. River rises of 2 to 3 feet...and even more on the
lower Penobscot...could be enough to break up ice. The combined
T/Td thawing degree index is showing the highest readings since
last December for the corridor from southern Piscataquis County
towards southern Aroostook County. At this time, northern zones
look OK, but if the warm surge advertised by the ECMWF comes to
fruition, a re-evaluation will be in order.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory until 8 AM EDT Friday for ANZ050>052.
&&
$$
Near Term...Hewitt
Area Forecast Discussion
National Weather Service Charleston SC
1013 PM EDT Thu Mar 28 2019
.SYNOPSIS...
High pressure will prevail through Saturday. A cold front will
sweep through Sunday, then a coastal low pressure system could
affect the area Monday and Tuesday. High pressure will then
build from the north.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Dew point depressions continue to shrink and with clear/mostly
clear skies and little to no winds away from the coast, the
probabilities of fog have increased. In fact there is now little
if any guidance that suggests that fog won`t happen. Fog
Stability Index (FSI) is forecast less than 20, RAOB radiation
fog probabilities are 60-75% and condensation pressure deficits
will be down to 20-30%. This will be enough for patchy fog,
mainly after 3 am and inland from the barrier islands with a
light onshore synoptic flow. There are definite indications that
some of the fog could become dense and even more widespread late
and near daybreak. But since it`ll be a struggle to even achieve
our cross-over temps, no mention is required at this time.
The low temp forecast is still on target, with lows 40-44F far
inland, 45-50F over the coastal counties, with even a few lower
50s on the beaches.
Previous discussion...
Other than to open up a slightly bigger range of low temps from
far inland to the immediate coast, the ongoing forecast is
humming along perfectly. Guidance still not in agreement on fog,
with the HRRR and CONS Short are the most "bullish" on its
formation, while most of the MOS guidance, the NARRE-TL and the
SREF have little if any developing. Should it form, ground fog
and maybe a little fog near rivers and marshes seems more likely
late.
Discussion from 328 pm...
The center of surface high pressure will remain over the
Carolina coast tonight with quiet and dry weather expected.
Clear skies will combine with calm winds to provide ideal
radiational cooling conditions. Lows are forecast to drop into
the low 40s inland, and near 50 at the coast. The main forecast
concern for tonight will be the potential for fog. Some of the
model guidance is hinting at fog developing late tonight towards
daybreak, primarily across southeast Georgia. Glancing at
forecast soundings, the moisture appears to be quite shallow
right at the surface. Also, crossover temperatures in the upper
30s to low 40s are not expected to be reached. Therefore, have
opted to keep any mention of fog out of the forecast for now.
Will continue to monitor trends this evening.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
Friday and Saturday: High pressure will prevail across the
Southeast, bringing dry conditions. Expect a warming trend with
temperatures several degrees above normal.
Sunday: A short wave and surface cold front will approach from the
west during the day. Expect a period of showers by late afternoon.
There is instability in place, so we maintained a slight chance of
thunderstorms.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
The front is expected to stall just off the coast Sunday night,
then a more potent southern stream shortwave will approach from
the southwest. Low pressure is expected to form along the front
off the FL/GA coast before moving up the coast. There continue
to be significant model differences with this system, but it
appears the best chance for precipitation will be Monday into
Tuesday. Cold advection during this time will keep high temps in
the low to mid 60s. Warmer and drier weather is anticipated
Wednesday into Thursday as high pressure expands across the
area.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Mainly VFR expected through 00Z Saturday. With little to no
winds, clear skies and a light onshore flow, there is a chance
for some patchy fog late tonight and towards daybreak. We`ll go
with a tempo of 5SM BR at KCHS and 3SM BR at KSAV from 08-12Z.
Conditions though could be worse at both sites.
Extended Aviation Outlook: Flight restrictions are possible Sunday
through Tuesday as a front, then a coastal low affect the area.
&&
.MARINE...
Overnight: High pressure will persist atop the local waters,
leading to a light gradient and generating NE and E winds around
10-15 kt or less. The only remaining Small Craft Advisory is on
the outer Georgia waters where seas will still be as high as 6
or 7 ft.
Extended Marine: The Small Craft Advisory for the GA waters beyond
20 nm should expire by Friday evening as seas subside. Otherwise,
high pressure through Saturday will keep winds relatively light.
Conditions will quickly deteriorate on Sunday, as a front moves
offshore and low pressure develops along it. Small Craft Advisories
will probably be needed during that time frame.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory until 8 PM EDT Friday for AMZ374.
&&
$$
NEAR TERM...
SHORT TERM...
LONG TERM...JRL
AVIATION...
MARINE...
Area Forecast Discussion
National Weather Service Dodge City KS
641 PM CDT Thu Mar 28 2019
...Updated aviation section...
.SHORT TERM...(This afternoon through Friday night)
Issued at 1200 PM CDT Thu Mar 28 2019
Initial cold front was passing through SW KS as of midday, beneath
a canopy of mid/high clouds. Post-frontal stratus will spread
southward behind the advancing boundary through this afternoon,
along with north winds increasing to 15-25 mph with higher gusts.
A large temperature gradient will result this afternoon, with
non-diurnally steady/falling temperatures north and mild 60s/70s
ahead of the wind shift across the southern counties. 12z NAM and
HRRR both show the cold front clearing the SE zones by 7 pm. The
odds of convection across the SE counties along the advancing cold
front appear very low this afternoon in a capped environment.
Widespread stratus and drizzle will prevail tonight in a moist
NEly upslope regime. NAM for the past several runs has shown its
classic drizzle QPF signature, so have high confidence that
drizzle will be widespread, especially after midnight.
Fortunately, temperatures tonight will stay well above freezing.
Forcing for ascent supportive of light rain will increase after
midnight, with measurable light rain most probable across the
northern counties. Temperatures tonight in the upper 30s and lower
40s. North winds will quite strong/gusty this evening, gusting
over 30 mph, before gradually diminishing after midnight.
Friday...Cloudy, damp and much colder. Followed the coldest NAM
solutions, with other guidance trending in the colder direction.
Stratus and NE winds will persist all day, with temperatures
essentially holding steady/struggling through the 40s. The north
winds, lack of sun, and areas of drizzle will make for a decidedly
raw day.
Upper trough centered with a 555 dm upper low in southern Wyoming
at 7 pm Friday, will weaken some to an open shortwave trough as it
enters the plains Friday night through Saturday morning. Still,
attendant jet stream energy aloft will enhance forcing for
precipitation Friday night into Saturday morning, with models
favoring most of this to fall across the northern zones.
Increased pop grids to the likely category, with light rain
spreading over SW KS Friday evening as shown by ECMWF. The second
much stronger cold front will arrive at the same time, with
increasing strong north winds and strong cold air advection
driving 850 mb temperatures down to -3/-4 C by 7 am Saturday.
As such, expecting a rain/snow transition to occur from north to
south Friday night. With the system weakening as it enters
confluent flow, and thermal questions regarding how fast the phase
change occurs, can`t get excited about heavy snow potential.
Still, nocturnal timing will encourage accumulations on at least
grassy surfaces, with 1-2 inches of wet snow possible mainly north
of US 50 early Saturday morning. Wet snow accumulations early
Saturday are most likely along the I-70 corridor.
.LONG TERM...(Saturday through Thursday)
Issued at 240 PM CDT Thu Mar 28 2019
Winter is not done with us yet, and we will be made aware of that
Saturday. Lingering snow showers will end quickly early Saturday,
followed by cold Canadian surface high pressure sinking southward
from the northern plains. Some sunshine is expected by afternoon
as subsidence eats away at the stratus, but still north winds of
15-30 mph will keep cold air advection persistent through the
day. Afternoon temperatures will be well below normal, only
reaching the mid 40s, with wind chills in the 30s.
A hard freeze is expected Saturday night through sunrise Sunday
morning. For many runs now, models have placed the 1035 mb
surface high directly over SW KS at sunrise Sunday. With few
clouds and light winds, near ideal radiational cooling is likely.
All locations will fall to at least the low to mid 20s. Loaded the
12z ECMWF bias-corrected guidance in the grids, which included
some teens on the higher terrain of the western counties.
Temperatures will begin to moderate Sunday, as the cold high
pressure exits eastward. Max temp grids still well below normal
for the last day of March, in the lower 50s. 12z ECMWF depicts a
closed low to sink SE into New Mexico daylight Sunday. Most, if
not all, precipitation with this system will stay south and west
of SW KS. Certainly, there will be an increase in cloud cover
across the SW zones. As the closed low passes to the south across
the Texas panhandle early Monday, there may be a rain/snow shower
near the Oklahoma border. This system appears moisture-starved,
with no impacts expected. Clouds will decrease Monday afternoon as
the low pulls away, allowing temperatures to rebound further into
the 50s.
Spring returns on Tuesday, with broad ridging and then SW flow,
with much warmer afternoon temperatures in the upper 60s and lower
70s. Mild, quiet and dry weather will persist into Wednesday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 638 PM CDT Thu Mar 28 2019
IFR to LIFR ceilings are expected overnight with a thick deck of
stratus. Visibilities may fall to around 2 miles around the DDC
and GCK terminals around midnight then be slow to burn off by mid
morning tomorrow. Winds will generally be from a northerly
direction, gusting to over 20 knots at times over the next couple
of hours.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 40 43 32 46 / 30 40 60 20
GCK 38 45 30 45 / 40 30 60 20
EHA 43 54 32 45 / 20 10 60 10
LBL 39 51 33 47 / 20 10 60 10
HYS 40 41 31 45 / 40 70 70 20
P28 49 52 37 49 / 30 40 40 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Hovorka_42
Area Forecast Discussion
National Weather Service Hastings NE
718 PM CDT Thu Mar 28 2019
.SHORT TERM...(This evening through Friday)
Issued at 347 PM CDT Thu Mar 28 2019
Aloft: RAP dynamic tropopause analyses and aircraft/AMDAR data
show split flow over N America. Over Canada...a ridge was in the W
with a trof in the E. Over the CONUS...a trof was in the W with a
broad ridge over the mid MS Vly. The Ern Canada trof has
delivered push of cool air returning temps back to more normal
lvls. A shortwave trof was moving onshore into CA. This trof will
move E into UT thru the night. This trof will develop into a small
low over WY/CO tomorrow.
Surface: The cool front that moved thru yesterday extended from
the GtLks acrs KS to a weak low over the OK panhandle. High pres
was sliding out of SA into the Nrn Plns. This high will expand
into the GtLks tomorrow as it weakens. Meanwhile...the cool front
will sink deeper into the Srn Plns.
Tonight: Cldy and should be quiet during the evening as a
shortwave ridge moves thru. Lift will increase after midnight as
the trof inches closer and a coupled jet structure evolves over
the rgn. Mstr is not fcst to be deep...so should see areas of drzl
develop S and W of the Tri-Cities.
Fri: Areas of drzl should expand acrs the rest of the CWA (N and
E of the Tri-Cities in the morning)...but some elevated shwrs
could develop as well. The main question is...will thunder occur?
For now left it out...but there will be some MUCAPE. During the
late afternoon...lift should become strong enough to saturate the
mid- lvls with a large shield of rain fcst to develop.
Temps will struggle to climb...maybe 3-5F above morning lows.
QPF: 0.10-0.25" during the daylight hrs.
.LONG TERM...(Friday night through Thursday)
Issued at 347 PM CDT Thu Mar 28 2019
Aloft: The WY/CO low will open up and cross the CWA Fri night
with NW flow gradually deamplifying Sat-Sun. Split flow will
remain over N America thru at least Mon...but mdl spread increases
significantly Mon-Tue as the last 2 GFS and GFS-FV3 are much more
amplified with the Nrn stream whereas the last 2 EC/GEM runs are
more zonal with consolidated flow. By Wed...spread decreases some
as all mdls indicate a progressive trof moving acrs the Wrn
USA...and into the Plns Thu.
Surface: A strong/chilly Canadian high will plunge S into the Nrn
Plns Fri night and into the CWA Sat. This will shove the front S
and E far away from the CWA. Uncertainty is higher than normal
thru early next wk...but the high should depart into the Ern USA
with svrl days of return flow. Low pres should begin organizing
over WY/CO Tue with a possible cold frontal passage Wed. The CO
low should be moving up the front into the GtLks Thu.
Temps: Much below normal Sat with highs in the 40s. Temps rise
back to normal Sun-Mon...warm to above normal Tue-Wed...then back
to normal Thu.
Precip: A large shield of rain should be over the CWA Fri eve. As
temp profiles cool...rain will change to wet snow from NW-SE.
These situations are always highly uncertain...try to time the
changeover. Snow accums hinge on it...which makes fcstg snow amts
very tenuous. For now...we cont to advertise up to 1-1.5" for
much of S-cntrl NEB from the Tri-Cities N and W. Less than 1"
elsewhere ...but this remains subject to change. If R changes to S
quicker than we are currently advertising...would not be
surprised to see 2-3" or even 2- 4" in some areas along or N of
I-80. Cannot overemphasize how uncertain this situation. Cont to
keep a close eye on the fcst. Total QPF: 0.15"-0.40".
After that...possibly some shwrs next Wed.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Friday)
Issued at 718 PM CDT Thu Mar 28 2019
General overview:
Confidence is high in a low-end VFR ceiling, VFR visibility and
mostly likely dry conditions through the first 12 hours. Then, the
latter half of the period Friday daytime becomes a bit more of a
question mark, as ceiling should gradually lower through the MVFR
range (perhaps even IFR late), along with increasing chances for
fairly widespread rain shower activity. There is an outside chance
that a bit of snow could start to mix with rain toward the extreme
end of the period (mainly at KEAR), but any possible accumulating
snow should hold off until after 00Z. Wind-wise, a remarkably
consistent direction and speed should hold through the vast
majority of the period, with direction northeasterly, sustained
speeds commonly around 12KT, and gusts in the 15-20KT range. Read
on for more details mainly regarding ceiling and precipitation
timing...
Ceiling/visibility/precipitation:
As mentioned, confidence is high in low-end VFR ceiling through at
least the first 12 hours, and probably closer to 18 hours
(especially at KGRI), although have started an MVFR ceiling at
KEAR as early as 13Z (medium confidence). Although a rogue rain
shower cannot be ruled out tonight, dry conditions appear more
likely until at least daybreak Friday, but even then have only
gone with "vicinity shower" mention until early afternoon. Then,
finally mid-late afternoon, confidence is high enough in a more
widespread/prevailing coverage of rain showers that have gone
prevailing -SHRA along with MVFR visibility. Went no lower than
low-end MVFR ceiling late in the period, but at least off-and-on
IFR is certainly possible, and have hinted at this with a "SCT008"
mention after 19Z.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
SHORT TERM...Kelley
LONG TERM...Kelley
AVIATION...Pfannkuch
Area Forecast Discussion
National Weather Service Goodland KS
520 PM MDT Thu Mar 28 2019
.SHORT TERM...(This evening through Friday Night)
Issued at 133 PM MDT Thu Mar 28 2019
19Z Surface analysis indicated 1024 mb sfc ridge sliding into
northern Nebraska with surface low developing near KPUB. Large
area of stratus in place across the forecast area, and this is
slowly sliding to the west over the past hour or so. Water vapor
imagery and RAP analysis indicates large closed circulation over
the PAC NW and short wave ridging across northern plains.
Pronounced dry layer also noted across southern portion of the
forecast area.
Precipitation chances and types along with fog potential will be
the primary forecast concerns through Friday night.
Initial change to the forecast was to diminish area of high
precipitation chances during the afternoon and overnight hours.
While several model databases are showing light QPF amounts
through the night, soundings strongly favor a drizzle type
pattern. While there could be some stray accumulations out there
tonight, dewpoint depressions will need to be overcome before it
would be a significant possibility and that will be difficult
with cloud cover and weak dry air advection. With increasing
forcing for ascent along the 310K isentropic surface (Around H7
WAA) there is some weak potential instabilty available tonight.
Should this level saturate, would see a few showers develop. With
that in mind, cannot totally remove chances for accumulating
precip and have limited them to areas where forcing/moisture
availability best line up. Should see any lingering precipitation
end after sunrise with a very similar pattern to today setting up
again tomorrow. Cool and cloudy conditions will prevail through
the day as initial precipitation shield lifts to the northeast.
As shortwave tough nears CWA after 18z, expect precipitation to
redevelop across western CWA and expand in coverage through the
evening. Precipitation will likely change to snow in the evening,
but warm ground and concerns about how fast cold air filters in
leads me to think snow amounts will be minor.
Other concern will be fog potential tonight. As mentioned earlier,
there appears to be overall dry air advection going on tonight,
although there are a few pockets of higher Tds up stream. THink
best potential for fog will be near current position of
cloudy/clear line. Surface here most likely to be preconditioned
for fog. Uncertainty still a bit high to issue any dense fog
products, but will need to monitor.
.LONG TERM...(Saturday through Thursday)
Issued at 133 PM MDT Thu Mar 28 2019
Synopsis... Some light snow/rain showers will be possible until
about midday Saturday. Accumulations are expected to be light, if
any, with maximum snowfall accumulations around an inch. Some light
rain/snow showers will also be possible late Sunday and early
Monday, mainly south of KS Hwy 96. High temperatures Saturday will
top out in the mid 40s before a significant warming trend along with
clearing skies brings temperatures into the mid to upper 60s by
Tuesday afternoon. Similarly, low temperatures early Sunday will be
in the low 20s before warming up to the low 40s by Wednesday
morning. The next chance for precipitation returns Wednesday and
Thursday. Wednesday is expected to be all rain, but the potential
exists for some snow to mix in early Thursday as low temperatures
drop back down around freezing overnight Wednesday.
Discussion... An upper-level longwave trough will be passing over
the Central High Plains Saturday which will lead to some increased
chances for precipitation lasting into the early afternoon hours.
This precipitation will fall in the form of snow early Saturday
before slowly mixing in with rain as temperatures warm up above
freezing mid-morning. Precipitation amounts are expected to be light
with generally around a tenth to two tenths of an inch of liquid
precipitation expected. Snowfall could potentially reach around an
inch in some locations in the Tri-State area, but with generally
warm temperatures and soil temperatures above freezing, snowfall
accumulation is expected to be light, if any.
A weak shortwave trough traversing over the Southern Plains region
Sunday could provide some chances for precipitation in the form of a
rain/snow mix Sunday afternoon into early Monday. However,
confidence is low for whether there will be any precipitation at all
in the forecast area during that time period. If there is any
precipitation, it is generally expected to fall south of KS Hwy 96.
After this weekend, strong upper-level ridging will build over the
western United States. This will lead to much quieter weather for
the Tri-State area in the beginning of next week. Mostly clear skies
and near-normal temperatures are expected this coming Monday and
Tuesday.
Increased precipitation chances return early Wednesday as
the next upper-level trough progresses eastward over the Pacific
Coast and heads toward the Central High Plains. This approaching
trough will provide enough upper-level support for ascent to bring
some cloudier skies and the potential for some light rain showers.
Temperatures overnight Wednesday into Thursday will return to near-
freezing levels, so it is conceivable that there will be some light
snow showers mixed in during that time, but for now forecaster
confidence remains low on this event given that it is so far out at
the moment. Either way, there is no real signal for any sort of
heavy snow or impactful weather event for Wednesday/Thursday. Light
showers and some breezy winds will likely be the main concern.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 520 PM MDT Thu Mar 28 2019
For KGLD and KMCK, sub vfr conditions are expected through the
period. Both terminals will see sub vfr cigs through the period
with KGLD seeing limited visibilities in drizzle/br from time to
time. Winds generally from the northeast 8-15kts, highest early in
the period.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...PATTON
AVIATION...99
Area Forecast Discussion
National Weather Service Marquette MI
740 PM EDT Thu Mar 28 2019
.SHORT TERM...(This evening through Friday)
Issued at 401 PM EDT THU MAR 28 2019
WV imagery and RAP analysis indicated cyclonic westerly mid/upper
level flow through the northern Great Lakes on the periphery of a
trough over Hudson Bay. At the surface, high pressure from southern
Saskatchewan/Manitoba into the northern plains was gradually
building into the region. 850 mb CAA has resulted in increasing
cu/sc over Upper Michigan this afternoon even as sfc temps have
climbed into the mid to upper 40s.
Tonight, sfc ridging will bring diminishing winds tonight along with
good radiational cooling under clearing skies. Temps should drop
into the teens over most of Upper Michigan with some single digits
possible over favored cold spots inland central.
Friday, Sunshine with 850 mb temps around -9C will allow temps to
rebound to the lower 40s. Expect lake breezes to develop, keeping
readings mainly in the upper 30s along the Great Lakes in the
afternoon.
.LONG TERM...(Friday night through Thursday)
Issued at 411 PM EDT THU MAR 28 2019
A fairly weak clipper system will work its way through Upper
Michigan overnight Friday into Saturday, bringing with it snow
showers, perhaps mixing with other precip types at times. With
Lake Superior fairly open and CAA filtering back in this weekend,
lake-enhanced snow showers look to return behind the clipper.
However, temps will rebound quickly on Sunday, with any lingering
precip due to a trough axis rotating through transitioning over to
rain. To round out the weekend, yet another quick-passing
shortwave/vort max will trek through on the backside of the
aforementioned trough axis, allowing for precip chances to
persist into the start of next week. For much of next week, looks
like the U.P. will be locked into a fairly unsettled pattern with
periodic precip chances, but anything that does fall will be light
in nature. The next system to watch will be a deepening low
pressure system crossing the region later in the week, with
widespread QPF looking plausible.
Temperatures will remain near or above normal through this
forecast period, with the coolest temps occurring Saturday into
Saturday night. Otherwise, Spring appears to be here with highs
generally in the 40s for much of the upcoming week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 739 PM EDT THU MAR 28 2019
VFR conditions are expected at all terminals during the forecast
period.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 401 PM EDT THU MAR 28 2019
West to northwest winds to 30 knots diminish at or below 20 knots
tonight into Friday. Winds increase again to 30 knots late Friday
night into Saturday from the north. Winds diminish to 20 kts or less
later Saturday night into early next week.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...lg
AVIATION...Voss
MARINE...JLB
Area Forecast Discussion
National Weather Service San Francisco Bay Area
900 PM PDT Thu Mar 28 2019
.SYNOPSIS...Isolated showers will continue overnight, but end by
daybreak Friday. High pressure will build over California through
the weekend, resulting in a drying and warming trend. Rain chances
will return late Monday into Tuesday. More widespread and
significant rainfall is possible by late next week.
&&
.DISCUSSION...As of 9:00 PM PDT Thursday...A line of intense
showers tracked across the San Francisco Peninsula late this
afternoon, producing brief very heavy rain, small hail, and at
least one report of thunder. Shower activity has since subsided,
with radar currently detecting only isolated showers. Most of this
remaining shower activity should end by midnight, although the
HRRR keeps a few showers going through late tonight. All
precipitation is expected to end by daybreak Friday.
Friday is forecast to be a mostly sunny, dry, and seasonably cool
day with highs mostly in the lower to mid 60s. Brisk northwest
winds will develop near the coast by late afternoon. Dry
conditions will prevail on through the weekend as an upper ridge
builds over California. Subsidence under this ridge is forecast to
warm 850 mb temps from about 1 deg C on Friday to 11 deg C by
Sunday. This will translate to a nice warming trend through the
weekend. By Sunday, expect widespread highs in the upper 60s and
70s.
Based on latest models, dry weather should prevail through at
least midday Monday. A relatively weak system is then expected to
bring showers to our area from late Monday into Tuesday. Rainfall
totals with this system are expected to be light, with greatest
rainfall amounts across the north. Longer range models indicate
the potential for a stronger and wetter system to impact our
entire area late next week and into the following weekend.
&&
.AVIATION...As of 04:32 PM PDT Thursday...for 00Z TAFs.
Borderline VFR/MVFR cigs the next couple of hours as showers
continue to move through. Observations show cigs generally between
3,000 and 6,000 ft AGL. Expect showers to diminish late this
afternoon but remain in the vicinity into late tonight. Cigs will
lift and become more widely scattered into this evening with VFR
conditions prevailing. Patchy MVFR cigs will be possible late
tonight into early tomorrow morning. SW winds to continue through
much of the period before winds shift out of the W/NW into
tomorrow afternoon.
Vicinity of KSFO...VFR conditions are generally expected with
SCT/BKN cumulus/stratocumulus decks around 3,000 to 6,000 ft AGL
through the early evening. Cigs and vis may lower to MVFR/IFR
with these current showers over the Peninsula. After this current
band of showers moves through conditions should improve with cigs
becoming more widely scattered. Scattered showers will remain
possible into late tonight. SW winds into tomorrow before winds
shift more W/NW into the afternoon.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR conditions to prevail with possible
MVFR/IFR cigs briefly late tonight into the early morning. W to SW
winds into this evening before turning SE late tonight.
&&
.MARINE...As of 8:11 PM PDT Thursday...Scattered showers will
continue into tonight across the coastal waters with rain chances
decreasing overnight. Generally light southwest winds will
continue overnight with winds gradually veering westward
throughout the day tomorrow. Northwest winds will return by
tomorrow night. Northwest swell will arrive tomorrow followed by a
longer period northwest swell Sunday evening.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tngt...None.
$$
PUBLIC FORECAST: Dykema
AVIATION: AS
MARINE: Rowe
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Area Forecast Discussion
National Weather Service Paducah KY
1016 PM CDT Thu Mar 28 2019
.UPDATE...
Issued at 1015 PM CDT Thu Mar 28 2019
Updated the forecast to reflect current radar trends. Showers
progressing into western portions of southeast Missouri and
southern Illinois appeared to be handled best by the latest
NAMNest and HRRR models, so massaged the forecast in that
direction for the rest of the night. This results in higher rain
chances further south into the forecast area, with an eventual
decrease in the activity across northern portions of the area
later in the night and towards daybreak. We should see another
round of activity impact especially the western and northern
portions of the area (southeast Missouri, southern Illinois,
southwest Indiana) during the daylight hours on Friday, when some
thunder is possible as well. Also raised low temperatures by a
degree or two. Otherwise, remainder of forecast is unchanged.
UPDATE Issued at 705 PM CDT Thu Mar 28 2019
Updated aviation discussion for 00Z TAFs.
&&
.SHORT TERM...(Tonight through Saturday night)
Issued at 209 PM CDT Thu Mar 28 2019
Thunder has been at least 3-4 counties removed to our northwest
today, but this will change with time. The first wave of energy
that shoots out along/over the boundary will occur this evening,
but it looks to keep thunder to our north, even if some of that
shower activity impacts our northwest, not dissimilar to what
occurred this morning.
Overnight, however, the models bring a few hundred Joules of
MUCAPE into mainly the northwest, so we introduce thunder there
(SEMO Ozarks), accordingly. This spreads eastward into the day
tmrw, but remains confined, primarily, to locations north and west
of the Ohio and Wabash rivers (SEMO/SIL).
Friday night-Saturday is when our best chance of rain, and
thunder, occurs, with the actual front and upper dynamical energy
coming together. Instability is still only marginally supportive
Friday night, but we do spread the thunder chance across the
entirety of the region by 12Z Saturday, as the front itself begins
to enter the FA. This front will be watched closely during the
day Saturday, as that will offer our best chance for stronger
storms, as one more wave of energy aloft rotates overtop the
eastward advancing front as it makes its way across western Ky.
SPC SWODY3 outlooks marginal risk svr storms for basically the
first half of the day Saturday...after which...fropa occurs and
the instability field is shifted to the east/ahead of the
boundary. The NAM and GFS offer similar solutions, winding the
thunder threat down by 21Z Saturday as the front has made fropa
over even our far southeast counties by then. Showers/clouds may
linger a little while longer in the post frontal cooling airmass,
as the upper trof doesn`t swing on thru for another 3-6 hours.
Storm total qpf still looks to be upwards/to around an inch for
many locations.
.LONG TERM...(Sunday through Thursday)
Issued at 209 PM CDT Thu Mar 28 2019
Cold air fills in behind the recently departed front, offering a
climo much below normal beginning to the long term portion of the
forecast. Sunday Highs will struggle thru the 40s, with 50s only
potentially reached in the far south. As high pressure increases
its grip across the Ohio river valley, clearing skies and
diminishing pressure gradient winds will result in ideal cooling
conditions for the coldest night Sunday night. Lows in the upper
20s north, to lower 30s south, combined with clear skies/light
winds, will promote frost/freeze conducive conditions, which may
impact any tender young early spring blooms.
The cool conditions continue during the first part of the week,
but do moderate into/thru the 50s/30s, on their way to slightly
warmer 60s/40s, during the mid week time frame. The next chance of
pcpn holds off til Thursday.
&&
.AVIATION...
Issued at 705 PM CDT Thu Mar 28 2019
Showers over Missouri and west central Illinois will continue to
drift to the east tonight. This activity will begin to impact our
western and northern terminals later this evening, with a gradual
southeastward shift overnight. Another round of showers and perhaps
a few thunderstorms is possible on Friday as waves of energy stream
parallel to a frontal boundary stalled just north of the region.
For the most part, VFR conditions will prevail albeit with lowering
cloud bases through the period. Some MVFR ceilings are possible
late tonight and Friday morning, particularly along and north of a
line from KCGI to KEVV. Southerly winds 5 to 10 knots tonight will
pick up to around 10 knots on Friday.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...RyanP
AVIATION...RyanP
Area Forecast Discussion
National Weather Service Reno NV
310 PM PDT Thu Mar 28 2019
.SYNOPSIS...
A couple of weak disturbances will bring scattered snow and pellet
showers with isolated thunder possible through this evening, and a
slight chance for rain or snow showers on Friday. For this weekend,
high pressure will bring dry and warmer conditions with light winds.
Next week a more active pattern is expected to return with periods
of valley rain, mountain snow and rain, and gusty winds.
&&
.SHORT TERM...
We trended low temps a few degrees cooler for Friday and Saturday
nights and reduced precip chances for Sunday night, but otherwise
no significant changes were made to the short term forecast.
An upper low off the Oregon coast with a shortwave rotating into
northern CA will bring a round of snow and pellet showers to the
Sierra, northeast CA, and parts of western NV, mainly from I-80
northward this afternoon and evening. A few of these showers could
produce isolated lightning strikes between 3-8 PM. We`re not
expecting anything close to yesterday in terms of travel impacts
over the Sierra, although short-term reductions in visibility and
minor slush or pellet accumulations remain possible toward sunset.
Some cool breezes will continue through this evening, with gusts
near 30 mph and Sierra ridge gusts near 50 mph.
For Friday, the trough axis is projected to stall over far northern
parts of CA-NV, leading to one more chance for light snow and rain
showers Friday afternoon. Coverage will be more sparse and limited
to northeast CA and parts of far northwest and west-central NV.
Instability looks insufficient for thunder Friday.
For the weekend, a ridge of high pressure will bring weather
optimal for many outdoor activities, with dry conditions and light
winds prevailing. Temperatures will rebound to near seasonal
averages on Saturday (highs near 60 for western NV valleys, and
near 50 for Sierra valleys) with further warming on Sunday (60s-
near 70 western NV and 50s near the Sierra). Cool nights will
continue with dry and mostly clear conditions through Saturday
night before increasing cloud cover brings milder lows for Sunday
night. Overall trends favor the ridge to hold on longer, delaying
the precip onset with the next storm until Monday or Monday night
so we removed most of the precip chances from Sunday night. MJD
.LONG TERM...Monday and beyond...
The first storm will move across northern CA and northern NV Monday
night through Tuesday night with a good chance of lower valley rain
and mountain rain and snow. This is initially a mild system and snow
levels will likely stay above 6000-6500 feet, and possibly higher at
times, through Tuesday afternoon before falling off as the upper low
approaches the region. Given the early April sun angle and current
timing of the upper cold pool, Tuesday evening/night is the most
likely time frame for accumulating snow for the main Sierra passes
and the Sierra valleys. For western NV, a quick burst of rain along
the front could produce 0.10-0.20". Gusty southwest winds (30-40 mph
for many spots) are expected to develop Tuesday for valleys. This
will result in rough lake waters and turbulence for aviators.
Tuesday night into early Wednesday, precipitation chances were
raised considerably as the 12Z EC/GFS are showing another piece of
upper level energy coming through the region. There is still some
question about whether the wave will move over the northern and
central Sierra or remain across far northern CA/NV (hence the low to
moderate chances); this will affect precipitation amounts and
whether or not showers can spill into western NV efficiently.
After early Wednesday, the next storm is due in sometime between Thu-
Sat with more wind and precipitation. AR tools continued to point
abundant moisture at the southern Cascades, with the moisture plume
advancing southward toward the northern Sierra with the next
trough/cold front. This system could be quite warm and wet,
especially from Tahoe northward; however, whether the storm flow
buckles more like the ECMWF (shorter duration) or stays more zonal
(longer duration) like the latest GFS will determine how progressive
and long-lived the moisture feed winds up. This in turn will greatly
affect precipitation amounts, flooding potential, and even wind
speeds (could be quite strong or only moderate) in the lee of the
Sierra. Confidence is quite low in precipitation amounts/impacts at
this time so consider this a heads up for now. Snyder/Hohmann
&&
.AVIATION...
Winds aloft, though not as strong as yesterday`s, continue to be
breezy with gusts reaching in the 40-50 kt range. This, along with
an increase in surface winds area wide, can contribute to some minor
turbulence and LLWS in areas for this afternoon. Expect these winds
to calm down overnight as low pressure lifts towards the northeast
and pressure gradients relax.
As for precipitation, scattered snow showers are anticipated for
later this afternoon through the evening hours mainly for KTRK/KTVL.
Latest run of the HRRR model has showers developing along the west
slopes of the Sierra, concentrated near the Tahoe Basin, by 02Z
dissipating by midnight. During this timeframe, MVFR CIGS/VSBY are
possible for KTRK/KTVL with little to no accumulation expected. For
other area terminals, a ~10% chance of an isolated snow pellet
shower is possible for the rest of the afternoon due to some leftover
atmospheric instability. Chances should diminish by sundown.
Weather conditions improve on Friday as ridging begins to build over
the region. Calm winds and decreased cloud cover will take place and
last through the weekend before the active weather returns once
again by Monday. -LaGuardia
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
Area Forecast Discussion
National Weather Service Springfield MO
706 PM CDT Thu Mar 28 2019
.SHORT TERM...(This evening through Friday Night)
Issued at 245 PM CDT Thu Mar 28 2019
Moisture is on the increase with a persistent south flow in place.
Low levels are still fairly dry with dew points in the 40s, but
moisture has increased enough in the 850-700mb layer with
steepening mid level lapse rates to produce enough elevated
instability/mucape for a few showers/isolated tstms. Coverage has
been minimal, but we have add a few lightning strikes up in the
Lake of the Ozarks recently. Expect more of the same this evening
and overnight with a gradual increase in moisture. Overall
coverage isn`t great, but will see cluster of elevated convection
tonight into Friday.
A slow moving front will sag south and extend from north
TX/central OK through se KS into central MO by 12z/7am Fri then
remain quasi stationary through the day Friday and into the early
evening. Model guidance varies on how much surfaced based
instability will be available. The 12z HRRR is more bullish with
mlcapes around 1000 j/kg over southeast KS and southwest MO during
the afternoon versus the GFS and high res NAM. However, all
guidance does at least show an increase in elevated instability
with steep mid level lapse rates. We expect an increase in
coverage of showers and thunderstorms late in the day and in the
evening as the a sfc wave and cold front move into the western
cwfa. Have the highest chances for showers/tstms during this time.
The severe risk will be conditional on the amount of surface
based instability that can occur. Hail and damaging winds look to
be the primary risks at this point favoring the western two thirds
of the cwfa, mainly Friday night.
Accumulated rainfall amounts may approach two inches over central
MO with lesser average amounts farther south. May have to look at
some hydro watch headlines for our northern counties at some
point. Right now progged rainfall amounts would probably be
marginal for a watch, but we will need to watch the evolving
forecast.
.LONG TERM...(Saturday through Thursday)
Issued at 245 PM CDT Thu Mar 28 2019
Saturday-Monday: A cold front will move through as the sfc wave
pushes off to the east late Fri night and early Sat. Post frontal
rain will linger for a time. Saturday will be a raw cloudy day.
Drier weather with colder than normal temperatures is expected
early next week with a couple of nights of near or below freezing
temperatures expected. Many areas will see lows in the mid/upper
20s.
Tuesday-Thursday: A warming trend is expected with readings
expected to get back to close to normal for early April. Some
guidance is spitting out some very light rain, but by and large
this period should be mostly dry through Wednesday. There are some
indications of a pattern change with southwest flow aloft ahead of
an approaching shortwave for Thursday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 644 PM CDT Thu Mar 28 2019
Scattered showers and thunderstorms will continue this evening
with additional thunderstorms possible overnight. Generally VFR
ceilings are expected during the evening with ceilings falling to
MVFR after midnight. Where storms do occur, ceilings and
visibilities may fall to IFR briefly.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...DSA
LONG TERM...DSA
AVIATION...Angle
For frequently asked questions about the Area Forecast Discussion
visit...
http://weather.gov/saltlakecity/general/afd_faqs.php