47.8°F
Current conditions from King Hill
Updated every 5 minutes
 
  Monday April 24, 2017

RSS Mesoscale Discussions from Storm Prediction Center

SPC - No watches are valid as of Mon Apr 24 17:12:01 UTC 2017

No watches are valid as of Mon Apr 24 17:12:01 UTC 2017.


No Mesoscale Discussions are in effect as of Mon Apr 24 17:12:01 UTC 2017.

SPC Apr 24, 2017 1300 UTC Day 1 Convective Outlook

SPC 1300Z Day 1 Outlook
      
Day 1 Outlook Image
Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0747 AM CDT Mon Apr 24 2017

Valid 241300Z - 251200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
THE EASTERN CAROLINAS....

...SUMMARY...
Thunderstorms will offer marginal severe-weather risk over parts of
the eastern Carolinas.

...Synopsis...
The most important upper-air feature for severe-storm potential will
be a mid/upper-level cyclone, now apparent in moisture-channel
imagery over much of AL and GA.  The associated 500-mb low,
initially near CSG, should track in a cyclonically curved arc near
MCN, SAV, CHS and MYR through the period.  As this occurs, the
related surface low -- analyzed at 11Z between CHS and NBC -- should
migrate slowly northeastward across the SC coastal plain today. 
Overnight, this low effectively should merge with an initially
separate, north-northwestward-moving surface cyclone now over
Atlantic waters north of the northern Bahamas.  The combined low is
expected to move inland over eastern NC by 12Z.  A cold front,
initially extending south-southwestward over northern FL and the
eastern Gulf, will shift eastward across SC south of the low, and
eastward over the FL Peninsula, through the period.  A sharply
defined warm front, initially from the low northeastward over NC
coastal waters, is expected to move slowly northward/inland through
the period.  The timing and inland extent of the front's progress
likely will be impeded more than most model progs indicate, by
rain/outflow reinforcement of boundary-layer static stability on its
poleward side. 

Meanwhile, a series of mostly low-amplitude, mid/upper-level
shortwave perturbations will traverse and reinforce a large-scale
trough, and related cyclonic flow covering much of the western and
central U.S.  Associated cooling aloft, steep lapse rates and
marginal low-level moisture, as well as low-level warm advection
tonight in the central Plains, should contribute to a broad swath of
potential for isolated to widely scattered thunderstorms from the
northern Great Basin and northern Rockies across the central Plains.

...Carolinas...
As the cold-core region of the mid/upper cyclone approaches, pockets
of surface heating occur in cloud breaks, and lapse rates steepen
atop available low-level moisture, a few bands or arcs of
thunderstorms are expected to develop episodically and move east-
northeastward across the outlook area.  Activity in the warm sector
will access pockets of high-theta-e marine air as well as impinge
upon the warm-frontal zone, while offering isolated hail near severe
limits, damaging gusts and a conditional/marginal tornado risk.  The
hail risk may extend somewhat poleward of the warm front with
elevated convection.  Minor coastward adjustments to the marginal-
severe probabilities (especially wind) are made over SC to account
for a slightly less-inland expected penetration of favorable
surface- and near-surface-based effective-inflow parcels, based on
the expected track of the surface low.  

Forecast soundings and the modified 12Z CHS RAOB suggest up to about
1500 J/kg warm-sector MLCAPE may develop, decreasing quickly along
and north of the warm front and under persistent convective cloud/
precip plumes.  Deep shear will remain modest, with a substantial
component of the mean flow parallel to the convergence zone(s)
providing convective-scale forcing.  This should contribute to a
dominant linear mode, with isolated bow/lewp formations and
ephemeral QLCS mesovortices embedded -- particularly near the warm
front where low-level vorticity, SRH and storm-relative flow all
will be relatively maximized.

..Edwards/Peters.. 04/24/2017

Read more

SPC Apr 24, 2017 1630 UTC Day 1 Convective Outlook

SPC 1630Z Day 1 Outlook
      
Day 1 Outlook Image
Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1050 AM CDT Mon Apr 24 2017

Valid 241630Z - 251200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
THE CAROLINAS...

...SUMMARY...
Thunderstorms will offer marginal severe-weather risk over parts of
the eastern Carolinas.

...Carolinas...
An upper low is currently centered today over GA, lifting slowly
northeastward.  Large-scale lift ahead of this feature is resulting
in rather widespread showers and thunderstorms over parts of
SC/NC/VA.  Northeasterly low-level winds, cool conditions near the
surface, and marginal CAPE will limit the risk of severe storms over
the majority of the region.  The possible exception will be near the
SC/NC coast where a weak warm front is poised.  Ample low-level
moisture and marginal surface-based instability may be sufficient
for an isolated cell to interact with the boundary and produce
damaging winds or perhaps a brief tornado later today.  An isolated
cell capable of hail is also possible this afternoon in vicinity of
the upper low center over western SC.  Both of these threat areas
appear to be quite marginal in nature.

..Hart/Cook.. 04/24/2017

Read more

SPC Apr 24, 2017 1730 UTC Day 2 Convective Outlook

SPC 1730Z Day 2 Outlook
      
Day 2 Outlook Image
Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1209 PM CDT Mon Apr 24 2017

Valid 251200Z - 261200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST OK
ACROSS SOUTHEAST KS AND INTO SOUTHWEST MO...

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF
EASTERN OK INTO WESTERN MO...

...SUMMARY...
Thunderstorms capable of large hail and damaging wind are expected
to develop across parts of northeast Oklahoma, southeast Kansas and
southwest Missouri Tuesday evening, and may persist into Wednesday
morning.

...Synopsis...
An upper trough will amplify across the southern Plains with strong
southwesterly flow aloft developing from TX into the mid MS valley.
At the surface, a low pressure trough will precede a cold front,
extending from western OK into central IA at 00Z, with dryline
extending southward across central OK and into TX. The front will
move southward overnight, to a north TX to central MO line by
Wednesday morning. Ahead of these boundaries, a moistening and
destabilizing air mass will reside, with dewpoints rising into the
60s.  Increasing wind fields as well as lift along the front will
result in a corridor of strong to severe thunderstorms beginning
Tuesday evening across northeast OK/southeast KS.

...Northeast OK...Southeast KS...Western MO...
Strong heating will occur across much of central and western OK into
southern KS, south of the cold front and along and west of the
dryline. Surface flow will be somewhat veering/southwesterly, but
winds will back by evening as a 50 kt low level jet core develops
generally east of I-35. Storms are expected to initiate near the
dryline/cold front intersection across south central KS or north
central OK, then increase in coverage and intensity during the
evening as lift increases along the front. Mean wind fields will
increase overnight with the main upper trough amplification. A
mixed-mode of supercells and linear/bows appears probable, with
large hail and damaging winds expected. The linear forcing mechanism
coupled with nocturnal timing suggest any tornado threat will be low
or brief.

..Jewell.. 04/24/2017

Read more

SPC Day 1 Fire Weather Outlook

SPC Day 1 Fire Weather Outlook
          
Day 1 Fire Weather Outlook Image
Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1134 AM CDT Mon Apr 24 2017

Valid 241700Z - 251200Z

...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EASTERN ARIZONA...MUCH
OF NEW MEXICO...AND FAR WEST TEXAS...

Small expansions have been made to the critical area across eastern
AZ and northern NM, where consensus of short-term model guidance
suggests sustained winds of 20-30 mph will combine with RH values
below 15% and dry fuels. The eastern extent of the critical area
across the southern High Plains is constrained by less receptive
fuels into the TX/OK Panhandles and west TX, although an elevated
fire weather delineation continues across these areas. The elevated
area has also been extended northward into south-central and
southeastern CO, where sustained winds of 15-25 mph will combine
with RH values of generally 14-20% and dry fine fuels. Locally
critical conditions may occur in the San Luis Valley of CO. For
additional details, see the previous discussion below.

An elevated area has been introduced across parts of the northern MS
Valley and Upper Midwest. A strengthening surface pressure gradient
and strong low-level jet across this region will support sustained
southerly winds of 15-30 mph through this evening, with higher gusts
possible. 12Z soundings and recent surface observations shows a dry
low-level airmass remains over this region from a prior frontal
passage. Even with high cloudiness limiting surface heating
somewhat, RH values will likely fall into the 20-30% range this
afternoon with diurnal mixing of the boundary layer. Although fuel
moisture is generally marginal to support large fire starts across
this region, the expected combination of strong winds with lowered
RH values supports an elevated designation.

..Gleason.. 04/24/2017

.PREV DISCUSSION... /ISSUED 1153 PM CDT Sun Apr 23 2017/

...Synopsis...
As an upper trough amplifies across the Four Corners region into the
southern Rockies, strong low/midlevel flow will spread from AZ
eastward into portions of NM and the southern High Plains in
conjunction with deepening low pressure in the lee of the Rockies. A
critical fire weather threat will result across portions of AZ, NM,
and west TX.

...Portions of AZ/NM and the adjacent Four Corners Region into West
TX...
Very warm and dry conditions are expected across AZ/NM, the adjacent
Four Corners region, and west TX this afternoon, with max
temperatures in the 70s-80s F expected at higher elevations and 90+
F expected at lower elevations. Minimum RH values of 5-15% in
conjunction with sustained westerly winds of 20-30 MPH will result
in critical fire weather conditions across eastern AZ, much of NM
and far west TX. Elevated conditions will extend into the Four
Corners region and also into a larger portion of the OK/TX
panhandles and west TX. 

...Portions of the Upper Midwest/Upper Mississippi Valley...
A strong low-level jet is expected to support strong and gusty
surface winds across portions of the Upper Midwest and Mississippi
Valley regions. High cloudiness may limit the amount of heating that
occurs in this area, but with a very dry residual airmass in place,
a modest amount of warming will result in elevated fire weather
conditions where dry fuels are available. An elevated delineation
may be required in the Day 1 update depending on short-term
observational trends.

...Please see www.spc.noaa.gov/fire for graphic product...

Read more


 
 
Current Radar Loop:

Copyright © WestfordWeather.net 2007-2017. All rights reserved.