Moderator: S2k Moderators
I've been raking debris out of the pool all day, and still had to backwash because the oak pollen balls clogged up the filter. Dave wasn't too happy to have to take the pump apart and dig crud out of the impeller either. 
Powerful storm system to impact TX today and Tuesday.
Strong winds today and tonight
Severe weather likely on Tuesday.
Discussion:
Deep upper trough still digging SE this morning over Arizona and N Mexico with downstream pressure falls noted over SW and W TX where surface low pressure will be developing. Pressure gradient at the surface is already tight and will tighten even more today as pressures fall to our west and low level jet cranks to an impressive 50-65kts at 925-850 mb…see wind section below. Capping noted this morning should keep rain chances limited to just weak showers under the cap for most of today.
Tuesday:
Powerful upper storm system moves across TX. Surface low will form in the Del Rio region and track ENE/NE toward the ARKLATX with tremendous wind energy. Low level jet will howl tonight into Tuesday with 60-70kts noted at 850mb with a 120kt jet streak rounding the SE side of the upper low over SC and SE TX on Tuesday. W TX dry line will fire off storms this evening and as surface low gathers and tacks eastward tonight lines of intense thunderstorms will develop from SC TX to NE TX. Slug of deep tropical moisture characterized by dewpoints in the upper 60’s and PWS approaching 1.6-1.8 inches will pour into SE TX this afternoon. PWS are forecast to rise to near record levels of 1.8-2.0 in on Tuesday which is over + 2 SD for mid March.
Severe:
Limiting factor appears to be instability given abundance of low clouds ahead of front. Forecast CAPE values of 500-1500 J/kg will be favorable for severe storms…however high levels of wind shear may be too much for only modest updrafts being produced by low instability. Warm sector also appears capped off with forcing and convection noted in models near and behind the surface cold front. This reduces the tornado threat as discrete supercells ahead of the main line appear low at this time. SPC has the entire region outlooked on Tuesday. Should instability be greater than currently forecast an upgrade to a moderate risk and higher tornado threat would be likely. Main threats will be wind damage as it will not take much to get surface winds of 60-80mph in the stronger storms.
Hydro:
Given near record setting PWS forecasted and slow nature of this storm system some heavy rainfall totals appear likely on Tuesday. Threat for training lines of thunderstorms as upper flow becomes parallel to surface boundaries during the day. With high PWS air mass expect high hourly rainfall rates of 1-2 inches. Basin wide totals of 2-3 inches appear possible and a few locations could see 4-6 inches especially where cell training occurs. For now no flash flood watch is needed…but we shall see how things unfold on Tuesday.
Wind:
Strong surface winds today through early Tuesday as strong low level jet roars just above the surface. Already seeing gusts of 35mph at Angleton, 33mph at Sugar Land, and 31mph at Port Lavaca this morning. With breaks in the overcast developing…expect to see some of the wind energy above the surface mix down today. Wind advisory is in effect for all areas and locations from Matagorda Bay southward will be close to high wind warning criteria this afternoon. Will go with gust to 40mph all locations and 45-50mph down the coast from Rockport southward where past experience on partly cloudy days with 65kt jet at 925mb does support these surface speeds. May also see some fairly strong winds Wednesday AM as backside of upper system crosses the area with NAM showing 40-50kts at 925mb before noon on Wed. Low level wind shear needed at all terminals today and especially tonight when mixing ends and surface layer decouples. Low cloud deck and strong winds may result in delays at the bigger airports today and Tuesday with onset of thunderstorms.
Long fetch southerly flow is producing sea level water rise along the coast along with increased wave action. Main concern has been from Galveston eastward into LA where SE winds are slightly more parallel to the coast allowing Ekman transport to the right to induce water level rise. Tide levels are currently running 2.0-2.4 feet above normal levels at Morgans Point and Clear Creek entrance. Galveston Bay storm surge operational forecast model maintains water levels around 2.0-2.5 feet above normal through Tuesday morning. Lunar influences should help push tides even higher and breaker run-up over time will also pile additional water on the beaches and into local bays. May see minor coastal flooding issues at high tides this afternoon and again Tuesday morning. We start to see problems in the bays and on the W end of Galveston at around 4.0 feet. Offshore Gulf buoys are running 5.0-7.5 feet and will rise to near 10 feet by this evening. Very dangerous boating conditions and poor swimming conditions with strong near shore rip currents as noted by 1 fatality yesterday and 4 coast guard rescues at San Luis Pass.
Powerful storm system moving toward TX.
Per SPC update this morning Day outlook has been upgraded to our west to moderate risk including threat of strong tornadoes. Upgrade for portions of slight risk area on Tuesday is possible as meso scale interactions evolve tonight and storms begin to fire along W TX dry line. Threat appears to be increasing for more supercells with increased tornado potential given backed low level flow ahead of deepening surface cyclone over SW TX. Threat of long lived corridors of damaging winds also appears to be increasing.
Wind advisory verifying at all locations currently with multiple stations gusting at or above 40mph. Gust of 41 at Bay City, 43 at Port Lavaca, and 45 at Port Arthur. Will continue to see sustained speeds of 25-30mph with gust at to slightly above 40mph through the evening. Given breaks in the overcast may see speeds bump up a little more this afternoon as vertical mixing ensues.
Per KLCH sounding cap appears to be a little too strong to allow storms to develop although we are starting to see some surface heating with low stratus breaking up some.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
505 PM CDT MON MAR 17 2008
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0500 PM NON-TSTM WND DMG ROBSTOWN 27.80N 97.66W
03/17/2008 NUECES TX PUBLIC
PALM TREE WAS BLOWN OVER AND DAMAGED THE FRONT HALF OF A
VAN. THE WINDSHIELD WAS SHATTERED.
SOUTH TEXAS REGIONAL WEATHER ROUNDUP
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
500 PM CDT MON MAR 17 2008
CORPUS CHRISTI CLOUDY 77 70 79 SE29G40
ROBSTOWN CLOUDY 79 68 69 SE36G47
KINGSVILLE NAS CLOUDY 80 69 69 SE25G40
Return to “USA & Caribbean Weather”
Users browsing this forum: No registered users and 49 guests
