Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/03/17
Area Forecast Discussion
National Weather Service Bismarck ND
930 PM CDT Tue May 2 2017
.UPDATE...
Issued at 928 PM CDT Tue May 2 2017
Quick update to blend to observed trends through 02 UTC. Little
change required from the previous forecast.
UPDATE Issued at 640 PM CDT Tue May 2 2017
Very little change with this update from the previous forecast.
The CAM consensus through the 22 UTC HRRR iteration is for
scattered showers with low but non-zero potential for
thunderstorms to continue past sunset across western North Dakota
with multiple weak impulses embedded in northwest flow aloft.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 312 PM CDT Tue May 2 2017
Scattered showers and isolated thunderstorms highlight the short
term.
An upper level wave and jet streak are responsible for providing
lift that is leading to scattered diurnal showers and
thunderstorms. Without any low level forcing only isolated to
scattered showers and thunderstorms are expected...mainly on the
east and west edges of the trough (James Valley and southwest ND
respectively). As the wave pushes further east tomorrow the bulk
of the precipitation should remain across east central and eastern
North Dakota.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 312 PM CDT Tue May 2 2017
A high amplitude ridge moves into the Northern Plains by this
weekend. This will lead to dry and warm conditions. Widespread
70s and low 80s seems reasonable. Dry and warm conditions could
lead to some fire concerns, but wind speeds should be minimal.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 928 PM CDT Tue May 2 2017
Scattered rain showers will continue across western North Dakota
through 04-07 UTC tonight. VFR conditions are forecast on
Wednesday with cumulus cloud bases lifting through the day.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...AYD
Area Forecast Discussion
National Weather Service Denver/Boulder CO
1004 PM MDT Tue May 2 2017
.UPDATE...
Issued at 1003 PM MDT Tue May 2 2017
Next wave is pushing south over the northern state border, helping
to spark off some new convection. COLMA system indicating some
in-cloud lightning as well, will have lightning in the forecast
for the next couple hours. After this wave, another wave and front
continues to be shown in models to push down tomorrow morning,
between 6 and 9 AM. Viewing latest model guidance, most models
keep snow levels above 6000 feet, however the HRRR wants to bring
a mix of rain and snow over the southern and southwestern Denver
suburbs tomorrow morning. With low temperatures and possible
further cooling with the wave and front, wouldn`t be surprised to
see some flakes fall mixing in. Will add in a mix of precip
tomorrow morning over the southern suburbs, as well as over the
Palmer and Cheyenne ridges.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 237 PM MDT Tue May 2 2017
The next storm system producing a mix of rain and snow in the
mountains, with scattered rain showers over the northeast plains.
The mid level trough axis will pass across the cwa through this
evening with weak ascent associated with it. Some instability as
well with a few lightning strikes detected over souther WY this
afternoon. The leading edge of a 120 kt jet max oriented north to
south will translate eastward across the cwa overnight as well. As
a result, snow showers are expected to continue in the mountains
tonight, with increasing coverage of rain showers across the
plains. Accumulations in the mountains tonight generally on the
light side with accumulation less than 3 inches, but locally
higher amounts possible with any thunderstorms. Heaviest showers
will likely occur prior this afternoon and evening, with
decreasing showers from west to east late tonight. The mdls
indicate a weak cold front will push south into Denver Wednesday
morning, 12-15z. Some lgt showers will continue through the
mid morning hours, then increasing subsidence will develop behind
the exiting trough by the aftn.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 237 PM MDT Tue May 2 2017
Upper level ridge over the western CONUS will produce a north-
northwest flow aloft over Colorado Wednesday night and Thursday.
For Wednesday evening, any precipitation associated with
Wednesday`s system is expect to be southeast of the area. Dry air
will move in overnight allowing for good radiational cooling and
chilly overnight temperatures. Expect lows to be in the 30s with
most areas staying just above freezing.
The ridge will slowly shift east late in the week. By 00Z Saturday
the ridge axis is expected to be centered over the Central Rockies.
Temperatures will warm Thursday and Friday with highs reaching the
upper 70s Friday across northeast Colorado. Dry conditions will
prevail under this ridge.
For the weekend and early next week, the ridge axis will progress
east of the state with a southwest flow aloft on Saturday. On
Sunday, flow aloft backs more southerly as an upper level low
moves into southern California. Moisture will start to increase
due to the southerly flow. Isolated to scattered thunderstorms
will be possible during the afternoon and evening hours. The best
chance for the convection will be over the higher terrain, which
will be closer to the upper level low. Chances for convection are
expected improve a little each day due to cooling aloft as the low
nears and increasing moisture.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 1003 PM MDT Tue May 2 2017
Showers increasing across the area with increasing ascent
associated with a passing wave. Mainly light rain showers with
isolated thunderstorms through 07z. Coverage not high enough to
include thunder in all the terminals at this time. VFR vsbys but
could see prevailing ILS cigs developing by 06Z and continuing
overnight, generally bkn-ovc 4-6 thousand ft agl. The ceilings
will drop to around 3 thousand ft agl if any heavier rain showers
dvlp. Surface winds should turn west/northwest around 10 kts after
this wave. Winds will weaken overnight with a secondary northerly
surge 12-14z Wednesday. Showers will be decreasing Wednesday mid
to late morning but lower cigs will linger until around 15z then
improve the rest of the morning. VFR with no restriction Wednesday
aftn.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Kriederman
SHORT TERM...Cooper
LONG TERM...Meier
AVIATION...Kriederman
Area Forecast Discussion
National Weather Service Dodge City KS
641 PM CDT Tue May 2 2017
...Updated aviation discussion...
.SHORT TERM...(This afternoon through Wednesday)
Issued at 1115 AM CDT Tue May 2 2017
Scattered mid layer clouds early this afternoon. Temperatures will
warm well into the 60s, to around 70 across the SE zones, but
remain in the 40s and 50s over the melting snowpack west of a
Dighton-Garden City-Hugoton line. Clouds will increase rapidly
this afternoon, as lift increases ahead of incoming shortwave.
Tonight...Rain. Atmosphere will reach saturation early this
evening, with scattered rain showers beginning around 7 pm.
Expecting rain to become widespread across the western 1/2 of the
CWA through 10 pm, and areawide by 1 am. Rain is a virtual
certainty across the southern zones by late evening, and raised
pops to the definite category (near 90%). 12z NAM/GFS are in
excellent agreement depicting strong frontogenetic forcing and a
mesoscale heavy rain band roughly from Liberal to Dodge City to
Pratt during the 1am-4am timeframe. Rainfall of 1-1.5 inches is
expected from this band, just in this three hour (1-4am) time
period. Ponding and lowland nuisance flooding is expected given
the wet soils. Shortwave trough will be strengthening as it
crosses SW Kansas tonight; as such, rain will be heavy at times.
However, elevated instability will be very limited north of the
KS/OK border. HRRR model solutions show a series of strong
thunderstorms with modest hail potential across the panhandles
into NW Oklahoma through tonight, staying mainly south of the CWA.
Can`t rule out some small hail in the strongest cores near the
Oklahoma border tonight. Lowest QPF tonight expected near I-70,
with around 1/2 inch of rain likely areawide, even outside of the
expected heavy rain band across the SE counties. Lows tonight in
the 40s, with low stratus clouds developing by sunrise Wednesday.
Wednesday...Breezy, showery and cooler. Primary forcing ahead of
shortwave will move well east of SW KS during the day. Still,
atmosphere expected to destabilize during the afternoon beneath
the shortwave trough. With 500 mb temperatures falling to -24C,
12z NAM forecasts CAPE near 500 J/kg and negative lifted indices
to -2C. Kept scattered showers and isolated thunder mentioned
through daylight Wednesday. North winds of 15-25 mph, gusts 30-35
mph, will combine with clouds to hold most locations in the 50s.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 130 PM CDT Tue May 2 2017
An extended period of dry weather is expected Thursday through
Sunday, offering SW Kansas a chance to dry out. Flow over North
America becomes very meridional and blocky starting Thursday, with
a strong closed low over the Mississippi valley and a strong high
pressure ridge building over Arizona. Dry NW flow aloft will
ensure a dry forecast on Thursday. Sharp upper ridge amplifies
over the Rockies on Friday, as strong upper low meanders over the
eastern U.S. Beautiful weather will result with few if any clouds.
Ridge axis phases east onto the plains Saturday, with more
sunshine and few clouds. Strong upper low near San Francisco
Saturday afternoon will be blocked and become stationary in
California on Sunday, in response to the blocking high pressure
ridge across the plains. There may be just enough peripheral
forcing on the eastern edge of this California cyclone to incite a
few late day storms over SE Colorado/NE New Mexico, and far SW
Kansas Sunday afternoon. Pop grids are very low along the Colorado
border Sunday afternoon. Not expecting much, if anything. Early
next week, medium range models including GFS/ECMWF bury the
western cutoff low over the Desert SW Monday and Tuesday, which
would continue to restrict the better forcing for convection west
of SW Kansas. The prospect for showers and thunderstorms should
increase the middle of next week (Wednesday and Thursday) as the
SW cyclone slowly edges out toward the plains, and ejecting
shortwaves interact with an established dryline.
A marked warming trend is expected Thursday through Sunday, with
lower to mid 80s forecast Sunday afternoon. This warming trend
will level off early next week, as the ridge axis phases east of
SW Kansas.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 641 PM CDT Tue May 2 2017
Showers and a few embedded thunderstorms will develop and move
across southwest Kansas during the overnight hours as an upper
level disturbance moves out of the the central Rockies tonight.
Cigs will gradually drop into the IFR category to occasionally the
LIFR category later tonight into Wednesday morning. Cigs should
gradually improve on Wednesday. There will be additional showers
and possible thunderstorms developing during the day.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 43 58 41 67 / 90 40 10 0
GCK 42 58 38 67 / 90 40 10 0
EHA 43 59 40 69 / 90 30 0 0
LBL 45 59 40 68 / 90 40 10 0
HYS 44 58 41 67 / 60 60 20 0
P28 50 60 44 69 / 90 40 30 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Gerard
Area Forecast Discussion
National Weather Service Lincoln IL
859 PM CDT Tue May 2 2017
.UPDATE...
Issued at 855 PM CDT Tue May 2 2017
Satellite data continues to show a decrease in clouds across the
forecast area early this evening as weak high pressure drifts in
from the west. Winds have decreased considerably as well as the
fair weather system drifts in. Keeping an eye on the temps and
the potential for some frost across the north towards morning.
Models have been consistently bringing cloud cover east into most
of our area in the 2am to 6am time frame, so other than the usual
"cold" spots that may pick up some patchy frost early Wednesday
morning, think the remainder of the area will have just enough
cloud cover move over early Wednesday morning to prevent any
threat for greater coverage of frost.
Our next storm system was tracking across the Plains this evening
with showers and thunderstorms tracking over the Oklahoma Panhandle.
Latest RUC model very similar to the operational models in taking
the initial band of rain east through central Missouri into
central Illinois just after sunrise. However, areas north of a
Jacksonville to Springfield to Paris line may not see much rain
during the morning as the dry air mass will remain in place as the
surface high drifts away from our area. As the shortwave trof
continues to dig and carve out a deep longwave trof over the mid
to lower Mississippi Valley Wednesday night and Thursday, we look
for a rapid increase in the precipitation across our area,
especially later tomorrow afternoon and night. As a northern stream
wave phases with the closed upper low over southern Missouri on
Thursday, the surface low will deepen even further over southern
Indiana and slowly track northeast into Ohio by Friday with windy,
damp and chilly conditions to round out the work week. Model
consensus continues to indicate rainfall totals will range from 2
to locally 3.5 inches, with the axis of heaviest rains unfortunately
about over the same areas that received the excessive rainfall from
a few days ago.
Made some minor adjustments to the cloud cover this evening as
well as overnight temperatures, especially in the east where it
will remain clear a little longer than the rest of the area.
We should have the updated zones out by 915 pm.
&&
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 323 PM CDT Tue May 2 2017
Shortwave over the Rockies will amplify strongly as it moves into
the Plains as a surface low develops and moves toward Arkansas during
the day Wednesday. As a result, clearing skies tonight with high
pressure moving over the area will be short lived as SE flow ahead
of the approaching system develops warm advection and frontogenesis
aloft to spread increasing rainfall rates over the area during the
day Wednesday. Have issued a flash flood watch from noon Wednesday
to midnight Thursday night.
In the shorter term, clearing skies, light winds, and the cool air
mass will lead to lows dipping into the upper 30s in areas
along/north of I-74. Localized areas of frost are possible, but
looks like any frost will be very isolated and short lived so will
abstain from any frost advisory at this time. Otherwise, lows mainly
lower 40s the remainder of the forecast area.
.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 323 PM CDT Tue May 2 2017
Models in fairly good agreement this 12Z cycle moving surface low
across the southern tip of IL Thursday 12Z with a strong deformation
zone/frontogenetical region producing steady moderate to heavy rain
across a preferred corridor primarily between I-72 and I-70
Wednesday night through Thursday afternoon. Rainfall totals look to
be 2 to 3.5 inches for this corridor and surrounding areas. Given
the very saturated conditions preceding this rainfall, flash
flooding will be easier than normal to initiate and ongoing river
flooding will be worsened. Have issued a flash flood watch for areas
roughly Mason County to Vermilion County southward. Kept isolated
mention of thunder Thursday south of I-70 as minimal instability
drifts across that area. With a slow movement of the system and some
trailing disturbances embedded northerly flow behind the main
trough, could be some lingering periods of showers in eastern areas
Friday and Saturday.
Strong gradients around the low will produce brisk northerly winds
Thursday and Friday, likely gusting over 30 mph. Highs will also be
quite cool in the northerly flow and rain cooled air, ranging from
low to mid 50s over most of the area Thursday, to upper 50s/low 60s
Thursday.
As the Wednesday/Thursday system moves east for the weekend, strong
northerly flow will persist for a few days, bringing continued cool
conditions with highs in the upper 50s to mid 60s Friday through the
weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 605 PM CDT Tue May 2 2017
Cumulus field continues to dissipate early this evening as we lose
daytime heating and surface high pressure approaches from the
northwest. VFR conditions are expected through Wednesday morning
before clouds lower and thicken mid to late morning from southwest
to northeast ahead of the next storm system that will bring another
round of significant rainfall to the area. Most of the sounding
data indicates lower VFR cigs will hold off until early afternoon
most areas. Main concern will be at SPI and DEC as models suggest
the rain, at least initially, will be pushing more east out of
Missouri in the morning and may affect those two sites in the 14
to 17z time frame allowing cigs to drop to low VFR by 17z. Further
north, the low levels will take longer to saturate so we expect
VFR cigs to continue into the afternoon hours. Surface winds will
become light and variable tonight, and then increase out of a
easterly direction at 10 to 15 kts by 21z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch from Wednesday afternoon through Thursday
evening for ILZ042>057-061>063-066>068-071>073.
&&
$$
UPDATE...Smith
SHORT TERM...37
LONG TERM...37
AVIATION...Smith
Area Forecast Discussion
National Weather Service Miami FL
836 PM EDT Tue May 2 2017
.AVIATION...
A cold front moving into the area, has brought showers and
thunderstorms to South Florida this evening. This activity should
begin to come to an end around midnight. Thunderstorm activity
will likely come to an end earlier, with the loss of daytime
heating. By tomorrow, conditions will be much improved, with the
exception of some possible showers and isolated thunderstorms
along the Gulf coast, impacting KAPF. Otherwise, VFR conditions
through the TAF period.
&&
.PREV DISCUSSION... /issued 743 PM EDT Tue May 2 2017/
UPDATE...
As of 740 PM EDT...A robust line of showers and thunderstorms
continues to move southeast through the central interior and
portions of the east coast metro. This line has produced gusty
winds, frequent lightning, and heavy rainfall as its moved
southeast. Earlier this afternoon, strong rotation was observed on
radar in west-central Palm Beach County, prompting the issuance of
two Tornado Warnings. These storms developed in response to a
frontal boundary located to the north interacting with abundant
moisture and instability across our region.
Additional scattered showers and storms will remain possible into
the late evening hours, although the current line is expected to
gradually weaken with time. Still for the next few hours, some
storms may continue to be strong with gusty winds, heavy rain, and
frequent lightning being the primary threats. HRRR rapidly
diminishes activity after 10pm, with only widely scattered showers
and perhaps a remnant rumble of thunder for mainly southeastern
areas.
PREV DISCUSSION... /issued 346 PM EDT Tue May 2 2017/
DISCUSSION...
Rest of Today and Tonight: A cold front is slowly making its way
down the Florida peninsula. Ahead of the front scattered showers and
storms continue to develop across the interior and working their way
into the metro area. Heavy rainfall and lightning are the primary
concerns. Some brief gusty winds will be possible with the strongest
storms, especially along any boundary collisions. Low temperatures
tonight will continue to be mild, ranging from the upper 60s in the
interior to mid 70s along the east coast.
Short Term (Wednesday-Friday): Tomorrow the frontal boundary will
wash out across the Lake Okeechobee region and with plenty of
remnant moisture as the drier air will not be able to penetrate into
South Florida. Scattered showers will be possible across the
interior and Gulf coast.
An upper-level trough moving across the central US into the OH/TN V
alley region will become cutoff by late Thursday. The trough on the
southern edge of the system will move down the Florida peninsula
Friday. Scattered showers and thunderstorms are possible as the
front moves across South Florida, especially during the day on
Friday. There continues to remain uncertainty in the amount of
showers and thunderstorms that will accompany the front, but with
the parent low located well to the north, the strong storm threat
looks minimal as the front gradually weakens with time. Temperatures
will be near to above normal during the short term period.
Long Term (Saturday-Monday): After the frontal passage, this weekend
high pressure will build into the Gulf on Friday. Wind will become
north/northwest and bring much drier air to the region. Relative
humidity levels drop into the low to mid 30s across the interior and
low to mid 40s along the coasts. Temperatures will be in the low 80s
over the weekend then warm up to mid 80s by the start of next week.
MARINE...
Winds will generally be southeasterly for the rest of today,
becoming east/northeasterly on Wednesday as a front washes out
nearby. Wind will be out of the southeast on Thursday. Development
of the Gulf breeze each afternoon will bring winds around to the
south to southwest along the Gulf coast. Scattered showers and
storms will be possible near the coasts in the afternoons and
evenings.
The front on Friday will bring south-southwest winds, along with
some 3-5ft seas in both the Gulf and Atlantic. Winds are expected to
diminish behind the front on Saturday.
BEACH FORECAST...
Current southeast winds and Atlantic beach observations support a
High Risk rip current risk. Winds will gradually diminish heading
into Wednesday as will the risk of rip currents.
FIRE WEATHER...
No significant fire weather concerns in the short term. Showers
and storms are possible Thursday night into Friday. This weekend a
much drier airmass will move in behind a frontal passage for the
weekend, with relative humidity values dropping into the mid 30s
for the weekend and beginning of next week.
&&
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 72 86 73 88 / 60 20 10 10
Fort Lauderdale 73 86 75 86 / 50 20 10 10
Miami 74 88 75 87 / 60 20 10 10
Naples 71 88 70 87 / 20 30 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk until 8 AM EDT Wednesday for FLZ168-172-
173.
AM...None.
GM...None.
&&
DISCUSSION...33/Kelly
MARINE...33/Kelly
AVIATION...13