November 2014: Nice Seanonal Thanksgiving Ahead

[SLM87TX]

What are the storm chances with this norther? will it be dry? or wet?

[srainhoutx]

Think this will be a glancing blow with the majority of the cold air headed to the east southeast. Could be record breaking for Florida. My opinion and it's not a professional one.

Normally I would agree in a typical year, but the Ensemble and Operational guidance is in above normal agreement that we will have a blocking regime across the Arctic, Eastern and Central N Atlantic that has been missing for many a year. Honestly I tend to use my words very carefully such as "suggest", "potentially"...etc. when dealing with our computer guidance, but even the HPC/WPC is 'buying' the solutions even with their normally conservative well reasoned analysis. If this upcoming pattern were to happen later in December or January, we could rival some of those infamous Arctic outbreaks of 1983/1989. That said it is only Mid November, so caution is advised regarding the sensible weather we can expect temperature wise at this time.

Edit to add the 12Z Euro which is in agreement with the 12Z parallel GFS in suggesting a potential Winter like storm that I mentioned this morning across the Panhandle crossing the Southern Plains later next week.

The attachment 11072014 12Z Euro f168.gif is no longer available

And just for grins...look what the long range Euro spits out...

[srainhoutx]

Technical analysis from the Climate Prediction Center for the Day 6 to 10 period...

PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST FRI NOVEMBER 07 2014

6-10 DAY OUTLOOK FOR NOV 13 - 17 2014

TODAY'S MODEL SOLUTIONS ARE IN EXCELLENT AGREEMENT IN PREDICTING A VERY
AMPLIFIED 500-HPA FLOW PATTERN OVER MOST OF THE FORECAST DOMAIN. THE MODELS
AGREE IN PREDICTING A STRONG TROUGH OVER THE BERING SEA. DOWNSTREAM OF THIS
FEATURE, RIDGING IS FORECAST ALONG THE WEST COAST OF NORTH AMERICA WHILE A DEEP
TROUGH IS PREDICTED OVER THE EASTERN AND CENTRAL CONUS. THE DETERMINISTIC RUNS
FROM THE GFS AND ECMWF ARE GENERALLY IN GOOD AGREEMENT WITH THEIR RESPECTIVE
ENSEMBLE MEAN SOLUTIONS. HOWEVER, TODAY'S 0Z DETERMINISTIC ECMWF AND TODAY'S
DETERMINISTIC 12Z GFS RUNS INDICATE A WESTWARD SHIFT OF THE PATTERN OVER THE
CONUS AND PULL THE PREDICTED TROUGH OVER EASTERN NORTH AMERICA MORE TOWARD THE
CENTER OF THE COUNTRY. THIS WESTWARD SHIFT IS SUPPORTED BY TELECONNECTIONS FROM
A POSITIVE HEIGHT ANOMALY CENTER OVER NORTHWESTERN CANADA IN TODAY'S MANUAL
HEIGHT BLEND. TODAY'S MANUAL 500-HPA HEIGHT BLEND IS COMPOSED PRIMARILY OF THE
ENSEMBLE MEAN SOLUTIONS AND IS BASED ON CONSIDERATIONS OF RECENT SKILL AND ON
ANALOG CORRELATIONS, WHICH MEASURE HOW CLOSELY THE FORECAST PATTERN RESEMBLES
CASES THAT HAVE OCCURRED IN THE PAST.

THE DEEP TROUGH PREDICTED OVER EAST-CENTRAL NORTH AMERICA STRONGLY FAVORS
BELOW-NORMAL TEMPERATURES FOR MOST OF THE CENTRAL AND EASTERN CONUS. HOWEVER,
NEAR-NORMAL TEMPERATURES ARE FAVORED FOR PARTS OF THE FLORIDA PENINSULA AHEAD
OF THE PREDICTED TROUGH AXIS. FORECAST RIDGING ALONG THE WEST COAST FAVORS
ABOVE-NORMAL TEMPERATURES FOR MUCH OF THE SOUTHWESTERN CONUS. ABOVE-NORMAL
TEMPERATURES ARE ALSO FAVORED FOR ALASKA UNDERNEATH ANOMALOUS SOUTHERLY FLOW
AHEAD OF THE TROUGH PREDICTED OVER THE BERING SEA.

MOIST FLOW AHEAD OF THE PREDICTED BERING SEA TROUGH FAVORS ABOVE-MEDIAN
PRECIPITATION FOR MUCH OF WESTERN AND SOUTHERN ALASKA. CONVERSELY, BELOW-MEDIAN
PRECIPITATION IS FAVORED FOR PARTS OF THE WESTERN CONUS IN ASSOCIATION WITH
PREDICTED RIDGING. PROBABILITIES OF BELOW-MEDIAN PRECIPITATION ARE ALSO
ENHANCED FOR MUCH OF THE UPPER AND MIDDLE MISSISSIPPI VALLEY DUE TO SUBSIDENCE
ASSOCIATED WITH THE TROUGH PREDICTED OVER THE EAST-CENTRAL CONUS. THERE IS THE
POTENTIAL FOR AN EAST COAST STORM TRACK AHEAD OF THE TROUGH AXIS RESULTING IN
ENHANCED PROBABILITIES OF ABOVE-MEDIAN PRECIPITATION ALONG THE IMMEDIATE
EASTERN SEABOARD. HOWEVER, THERE IS STILL MUCH UNCERTAINTY AS TO THE DETAILS OF
ANY SHORTWAVE TROUGHS THAT MAY DEVELOP. ABOVE-MEDIAN PRECIPITATION IS ALSO
FAVORED FOR THE GULF COAST REGION AND PARTS OF THE SOUTHERN PLAINS AND SOUTHERN
ROCKIES AROUND THE BASE OF THE PREDICTED LONGWAVE TROUGH OVER EAST-CENTRAL
NORTH AMERICA.

TODAY'S OFFICIAL 500-HPA BLEND CONSISTS OF 15% OF TODAY'S 0Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 15% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8, 10%
OF TODAY'S OPERATIONAL 6Z GFS CENTERED ON DAY 8, 20% OF TODAY'S 0Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 8, 10% OF YESTERDAY'S 12Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 7, 15% OF TODAY'S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8, AND
15% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8


MODEL OF THE DAY: 0Z ECMWF ENSEMBLE MEAN

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: MUCH ABOVE AVERAGE, 5 OUT OF 5,
DUE TO GOOD MODEL AGREEMENT AND A PREDICTED AMPLIFIED PATTERN.

The attachment 11072014 CPC Day 8+ Analogs 610analog_off.gif is no longer available

[Kingwood32]

When r we expecting this artic front?

[skidog40]

Time to can up, ice age is here

[srainhoutx]

When r we expecting this artic front?

The front should sweep across Texas beginning during the day Monday and clear the Coast Tuesday morning.

[srainhoutx]

Extratropical Tropical Storm Nuri surpasses the lowest pressure recorded in Dutch Harbor, AK in October 1977 by 1 MB. The reading recorded in October 1977 was 925mb and ET Nuri is now 924mb with the latest analysis.

[srainhoutx]

No significant change in the upcoming work week forecast. A early season Arctic front arrives late Monday across the Panhandle and sweeps of the Coast of Texas Tuesday. The computer guidance is trending slightly stronger with a 1050MB+ Arctic High Pressure cell settling into Montana allowing unusually early season cold to plunge S into the Plains. The medium/longer range guidance is indicating a reinforcing shot of very cold air arrives later next week with some temperature departures from normal may near the -30 to -40 degree range East of the Continental Divide.

[srainhoutx]

Updated Extended Outlook from The Weather Prediction Center tells the tale regarding this early season Arctic Airmass...

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1058 AM EST SAT NOV 08 2014

VALID 12Z TUE NOV 11 2014 - 12Z SAT NOV 15 2014


...MID-WINTER IN MID-NOVEMBER...

WHILE IT WILL BE FAR FROM MILD UNDER THE BIG ARCTIC HIGH NESTLING
INTO THE CENTRAL UNITED STATES, NORTHERN INTERMOUNTAIN REGION, AND
GREAT LAKES AND NORTHEAST, THE WEATHER FORECAST AT LEAST WILL BE
RELATIVELY UNCOMPLICATED. IT IS THE FLOW AROUND THE EDGES OF THE
POOL OF COLD AIR THAT PRESENTS THE SIGNIFICANT FORECAST CHALLENGE
THIS PERIOD. THE HIGH LATITUDE OF THE POSITIVE HEIGHT ANOMALY THAT
IS PART OF THE MACHINERY BRINGING THE EARLY CHILL WILL TEND TO DO
TWO THINGS TO THE FLOW MUCH FARTHER SOUTH: FIRST, LOWER HEIGHTS
OVER THE SOUTHWESTERN UNITED STATES. SECOND, MAINTAIN A RIDGE OVER
THE SOUTHEAST. BOTH OF THESE FEATURES ON THE PERIPHERY OF THE
SURFACE HIGH SHOULD LEAD TO GREATER PRECIPITATION IN THOSE AREAS.
THE WET SWATH IN THE WEST WILL EXTEND FROM NORTHERN CALIFORNIA AND
OREGON SOUTHEASTWARD TO THE RIO GRANDE. IN THE EAST, THE ATLANTIC
STATES FROM FLORIDA TO EASTERN NEW ENGLAND WILL BE VULNERABLE TO
PRECIPITATION FROM ANY WAVE OR WAVES THAT RIDE THE BAROCLINIC
ZONE.


CISCO

[srainhoutx]

A cool morning in NW Harris County with temperatures is the mid to upper 40's will warm up to the comfortable 70's today under sunny skies. Tomorrow will continue to warm as we begin to feel the response to the much advertised pattern change to a much colder pattern by Tuesday evening across the Lone Star State and much of North America. We are expecting a Omega Blocking Pattern that has several feature involved. Extratropical Storm Nuri played an important role in beginning the process of buckling the jet stream across N America, but other factors are in play such as tropical forcing, a robust Madden-Julian Oscillation (MJO) as well as rather strong Convectively Coupled Kelvin Wave (cckw) across the Pacific. At the High Latitudes across the North Pole and Arctic, very strong High Pressure extends across that area known as an Omega Block. Ridging in Alaska allows very cold air that has been building across Eurasia/Siberia to be pulled across the N Pole and plunge very far S into the United States and even Mexico. The blocking pattern extends into the NE Atlantic Ocean that does not allow the cold air to move E that far off the E Coast into the Atlantic as wee typically see in Winter. The main issue is this blocking regime does not appear to be transient and will be in place into the extended range that may well last into the week of Thanksgiving. If this blocking pattern persists, reinforcing shots of very cold air will continue to drop S in fairly rapid progression with the arrival of additional fronts about every 4-5 days. The main concerns are the embedded upper air disturbances under cutting the Western Ridge as well as those dropping S from Western Canada. Add to the mix a noisy sub tropical jet with over running moisture and upglide precipitation and you have a recipe for a very complicated forecast that is typical of a weak El Nino year. There will be periods of moderation, but the appear to be very short lived and the disturbances cross the Inter Mountain West and Plains will begin to lay down snow leading to less and less airmass modification as time goes on.

The attachment 11092014 00Z Euro GFS Compare test8.gif is no longer available

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1234 AM EST SUN NOV 09 2014

VALID 12Z WED NOV 12 2014 - 12Z SUN NOV 16 2014

...RELOADING UPPER PATTERN TO CONTINUE TROUGHING/COLD OVER MOST OF
THE CONUS...

...OVERVIEW...

WELL-ADVERTISED COLD SNAP WILL LEAD THE MEDIUM RANGE PERIOD
MIDWEEK NEXT WEEK AS STRONG RIDGING /500MB HEIGHT STND ANOMALY
NEARING +4 WHICH IS VERY RARE/ HOLDS OVER NORTHWESTERN NORTH
AMERICA. THIS FAVORS TROUGHING TO ITS SOUTHWEST AND SOUTHEAST IN
AN OMEGA BLOCK PATTERN... LOCKING IN THE COLD FOR MOST OF THE
CONUS OUTSIDE THE WEST COAST BUT PARTICULARLY FOCUSED OVER THE
CENTRAL STATES.

...GUIDANCE PREFERENCES...

SYNOPTIC AGREEMENT REMAINS GOOD AMONG THE 18Z PARALLEL GFS AND 12Z
ECMWF/ECENS MEAN... AND THEIR BLEND WAS USED AS THE BASE TO THE
FORECAST. THE DETAILS TO BE IRONED OUT LIE WITH THE EXODUS SPEED
OF THE UPPER TROUGH THROUGH THE NORTHEAST ON FRIDAY /WHERE THE
ECMWF MAY BE OVERLY WRAPPED UP/ AND ALSO THE STRENGTH OF THE RIDGE
ALONG THE WEST COAST UP INTO ALASKA. ECMWF ENSEMBLE MEMBERS
SUGGEST A STRONGER AND MORE RESILIENT RIDGE THAN THE GEFS MEMBERS
AND GIVEN THE LEAD-IN WAS INCLINED TO SIDE WITH MORE RIDGING
UPSTREAM WHICH SUPPORTS MORE DIGGING DOWNSTREAM INTO THE ROCKIES
BY THE END OF NEXT WEEKEND. 12Z GFS WAS NOT TOO FAR FROM THIS
CLUSTER OF SOLUTIONS AS WELL. THIS WOULD SUPPORT CYCLOGENESIS IN
THE UPPER MS VALLEY BY SUNDAY.


...SENSIBLE WEATHER HIGHLIGHTS...

PRECIP WILL FOCUS ALONG/AHEAD OF THE ARCTIC BOUNDARY PUSHING OFF
THE EAST COAST ON WEDNESDAY AND ALSO BACK THROUGH THE ROCKIES
WHERE THE COLD AIR WILL SPUTTER OVER THE DIVIDE. LAKE-EFFECT SNOW
SHOULD FLY IN EARNEST WITH NW FLOW OVER THE REGION AND A SFC-850
DELTA T OF ABOUT 15-20C. ENERGY THAT WILL SLIP BETWEEN THE RIDGE
CENTERS WILL SERVE AS THE MAIN PRECIP AREA WED-THU AS IT PUSHES
INTO OREGON AND NORTHERN CALIFORNIA. THE COLD TEMPERATURES REMAIN
THE TOP STORY WITH 30-40F BELOW AVERAGE TEMPERATURES POSSIBLE FROM
MT SOUTHEASTWARD AND EVEN 20-30F BELOW AVERAGE INTO TEXAS. SOME
RECORD LOW MINS/MAXES ARE POSSIBLE. SECONDARY SURGE NEXT WEEKEND
SHOULD BE INTERRUPTED BY BRIEF MODERATION BUT STILL COLDER THAN
AVERAGE FOR MID-NOVEMBER.


FRACASSO


The forecast late in the week is already presenting some challenges as a fairly strong upper air disturbance arrives from the Western US into the Southern Rockies/Southern Plains. There are some indications that a wave of low pressure may develop along the Lower Texas Gulf Coast and spread moisture over a shallow Arctic airmass at the surface. The best chance for wintry mischief will be across the Panhandle and Oklahoma and on E into Arkansas. As always we cannot not accurately predict what the sensible weather will be beyond the day 2 to 4 day range and as we know, that can even be challenging.

After a rather long and quiet period on our Weather Forum, it does appear that we may have an interesting pattern and as we know over the years, Tropical and Winter Weather bring the most attention to our Weather Community. Our newly registered members increased this past week as a testament that people are following and interested in joining and we welcome them to jump in and participate. This Weather Forum is a fairly relaxed and an educational venue that laymen and novice can follow and participate freely as well as gain the knowledge of our very seasoned Professional Meteorologists and very knowledgeable weather enthusiasts that bring literally decades of experience to our Board.

[jasons2k]

The media have already latched on to "The Polar Vortex" with this first polar front.

Where is Chris Farley when you need him for a good laugh? I can imagine it now... "The voooooooooortex is coming!"

[wxman57]

The front should reach Houston around noon Tuesday. There won't be much moisture ahead of it, so no storms.

[srainhoutx]

Briefly looking ahead to next weekend, the guidance is trending to a solution that suggests a rather robust upper air disturbance crossing New Mexico into the Panhandle/N Texas and Oklahoma. A Coastal Low signal is suggested by the various operational suite of Global computer guidance that may bring a true cross Polar flow straight S along the Rockies into the Plains as the winter like storm departs.

[srainhoutx]

Afternoon briefing from Jeff:

Prolonged period of below to well below normal temperatures heading for much of the central and eastern US this week including TX.

Surface high pressure is gradually moving eastward this afternoon with surface winds swinging around to the south and southwest over the area. Winds will increase from the south on Monday and this will result in a fairly warm day with highs in the 70’s across much of the area. Monday will be the last day of highs in the 70’s likely for the next 10-15 days across the region.

US upper air pattern will undergo significant amplification along the US west coast into western Canada and blocking over the Atlantic Ocean in response to the extremely intense extra-tropical cyclone (ex-super typhoon Nuri remains) over the northern Pacific Ocean. Significant ridging along the west coast will dislodge a pool of cold polar air in NW Canada and send in quickly down the front range of the Rockies early this week. The trough being carved out downstream of the ridge over the central US is fairly significant for mid-November with below mid-level heights on the order of 2-3 standard deviations from normal. This will result in a strong polar air mass reaching the US Gulf coast and by Tuesday. Powerful cold front will enter TX Monday evening and sweep quickly off the TX coast Tuesday. Temperatures ahead of the front will be in the 70’s and fall quickly into the 50’s and even 40’s behind the front. Moisture looks fairly meager with the boundary and while forcing will be strong, will not go any higher than 30% for a line of showers mainly toward the coast.

Gusty north winds and strong cold air advection will be in place Tuesday night into Wednesday. Some of the guidance is suggesting a period of about 12-24 hours of weak overrunning clouds as WSW mid-level flow brings moisture over top of the surface cold dome. Any cloud cover will have effects on daytime highs and overnight lows. It is possible that coastal locations could remain mostly cloudy on Wednesday with highs staying in the 50’s. Overrunning regime should end Thursday as deep polar high builds into TX. Clearing skies and lighter winds will result in near excellent cooling conditions Thursday night. With dewpoints in the upper 20’s to lower 30’s a few locations north of I-10 will likely fall to freezing. GFS guidance is showing a low of 29 for Conroe, 32 for College Station, and 35 for IAH Friday morning. Will need to watch this period very closely to see if more widespread freezing conditions are possible. Freezing conditions are likely Friday morning across much of central and north TX.

Cold air will remain locked in place into next week as downstream blocking in the upper air pattern over the Atlantic keeps cold fronts moving southward preventing air mass modification. Undercutting sub-tropical flow and position of the polar highs suggest a fairly potent short wave drops through the mean trough next weekend. With cold air locked in place at the surface mid level moisture will begin to overrun the cold dome on Saturday resulting in increasing clouds and by late afternoon showers developing from SW to NE across the region. Latest GFS run is very aggressive in moisture return late Saturday. Coastal troughing is possible Saturday night into Sunday with rain chances increasing as moisture pours into and over the cold air mass at the surface. This will likely result in very raw conditions by Sunday with highs likely not getting much above 50 with clouds and rainfall. There is some potential for P-type concerns over W/NW/N TX late next weekend where the air will be colder, but all rain for SE TX.

Departing storm system early next week potentially grabs a batch of arctic air over Canada and brings it southward down the plains keeping cold conditions in place through Thanksgiving week as downstream blocking remains in place over the Atlantic.

[Katdaddy]

Temps in the upper 40s and 50s across SE TX this morning. The well advertised cold front arrives tomorrow followed by highs in the 50s and low in the upper 30s and 40s. A 40% chance of thunderstorms tomorrow ahead of the front with slight chance of showers Wednesday. Its possible that areas N of Houston could experience their first freeze. This mornings Houston-Galveston AFD is quite interesting:

AT THE SFC HIGH PRESSURE BUILDS OVER THE PLAINS WITH STRONG COLD ADVECTION. ECMWF KEEPS A SIMILAR PATTERN AT THE SFC WITH HIGH PRESSURE OVER THE PLAINS BUT WEAKER COLD ADVECTION. ALOFT THE ECMWF BRINGS A VERY POTENT SHORT WAVE THROUGH N TX AND SPREADS QUITE A BIT OF
MOISTURE FROM THE GULF OVER THE COLD AIRMASS. THE RESULT WOULD BE WINTER WEATHER CONDITIONS PARTICULARLY NEXT MONDAY OVER N TX. RIGHT NOW WILL STICK CLOSER TO THE GFS SOLUTIONS BUT WILL BE INTERESTING TO FOLLOW FUTURE MODEL RUNS TO SEE WHAT DEVELOPS.

[snowman65]

Is it too soon to start a Thanksgiving weather potential thread? Or if any pros want to chime in on what we "may" expect? Speaking in terms of temps....Thanks!

[srainhoutx]

Is it too soon to start a Thanksgiving weather potential thread? Or if any pros want to chime in on what we "may" expect? Speaking in terms of temps....Thanks!

Sure. Why not. We can tweak the forecast as the next 17 days unfold. Many have travel plans as well as family Thanksgiving festivities, so many will want to know the specifics of a Thanksgiving forecast as well as the big HEB Thanksgiving Day Parade in Downtown Houston that will be carried live by KHOU...

[tireman4]

This will be an interesting November. We shall be watching quite closely...Have fun.....

[BlueJay]

To bring the potted plants indoors or NOT to bring the potted plants indoors. That is the question.

In the past David Paul has recommended that deeply watering your outdoor plants may protect them from freezing.

I think later on this afternoon, I will bring in the smaller plants and deeply water the others.

I can't believe winter is already here! BRRRRRRR!!!

[jasons2k]

Potted plants will freeze faster than plants in the ground. It will be a close call.

Geez I'm not ready for this yet. I like the 50's-70's weather, especially for November. It's not supposed to be this cold yet!