Archive for April, 2008

Quick outlook for Thursday, May 1st

We visited National Weather Center (NWC) in Norman yesterday and met up with Senior Research Scientist dr. Charles Doswell III from Cooperative Institute for Mesoscale Meteorological Studies (CIMMS). We had a nice discussion about offices and stuff in NWC. Thanks again for your time, Chuck! I also met Greg Stumpf and Ernani Nascimento (both ESTOFEX members) at NWC later.

Then we continued north to Oklahoma City for some shopping. Ended up in Guthrie, OK where we spent a night. It was pretty windy with some nice southerly wind gusts yesterday, about 15-20mph sustained winds, gusts above 30mph.

Outlook for today says southerly to souteasterly winds will increase which will hopefully cause quicker moisture return from the Gulf of Mexico. Currently there are around 60F dews on TX coast and mid 50s F in south Oklahoma shifting north. That actually is not that bad, giving us a hope to get low to mid 60s F over NE Oklahoma into SE Kansas tomorrow later afternoon. Though this is still pretty conditional attm, all depends on LL jet if it will make its job done. There are still slightly too SW directions of mid-level jet, we definatelly need more southerly directions to bring better moisture northwards.

We will be probably targeting NE Oklahoma, likely just northeast of here, depends on the next model runs simulations. Things are still too conditional over here, as strong cap could hold all and there could be a bust day. Hopefully not!

Long-term outlook for the days after this system, for Saturday, Sunday etc are quite impressive with juicy moisture return into west-central TX and Panhlandle. That could give us some nice chasing days over there with dryline play.

First chilling day and Thursday outlook

We have moved from Dallas, TX to Norman, OK today. Not much happened on the road, but at least we had a good sleep last night, we just needed it. Tomorrow there is another calm day, sunny weather predicted with temps finally approaching +30°C, it was about a time! =)

I will just put some outlook updates for Thursday now, as there is not much to talk about Wednesday chase, if there it will be. It does look that there will be some precipitation breaking in NW Kansas along I70, somewhere east of Goodland, but surface dewpoints are only in the upper 40s F, which is not impressive at all. It may also remain capped through all the day. We will see if there are better chances on the next model runs and decide if its worth to go up north, just to have a training chase before Thurday.

Thursday looks like to have a great potential for an outbreak of some possibly strong tornadoes over eastern Kansas into NE Oklahoma. However its still not easy to pick up the target, as models, especially GFS and WRF are quite different on the latest runs, GFS has triple point in NE Kansas, while WRF has it in NE Oklahoma. I am focusing on WRF as I prefer its maps for closer days.

There is a narrow coridor of precips breaking just south of the triple point along the dryline in NE Oklahoma. Deep-layer shear is pretty impressive there, might be over 50kt easily! This run was actally pretty confident with breaking out the precipitation, the CAP holds until the mid-afternoon time, 700mb temps are only around +7°C in that time. As it can be seen on the maps below, moisture returns north into SE KS with surface dewpoints into the low 60s F…

dewpoints

Nicely backed winds just east of the dryline over NE Oklahoma and 850mb winds of 30-40kt from SSW direction are simply incredible for relative low-level storm infow, this makes a favorable 0-1km wind shear for tornadoes.

surface dewpoints

850mb theta-e and winds

SBCAPE is exceeding 3500 J/kg over narrow coridor in NE Oklahoma, that will be our target if this setup survives through the next runs from the models. But its still 84h ahead, so doing any final conclusion would be just too optimistic.

SBCAPE

Surface winds and theta-E map has some impressive values, strong heating just south of the triple point and good backing winds over there.

surface theta-e

We will see how things are going through the next runs, I will keep you updated. Definatelly we will be out chasing… if not in NE Oklahoma, where the best potential for long-tracked tornadic supercells exist, we will be in NE Kansas or SW Iowa, where another triple point and good supercell potential will likely take place, but wind shear isn’t that impressive up there.

Here is the outlook from Storm Prediction Center for Thursday…

DAY 4-8 CONVECTIVE OUTLOOK
  NWS STORM PREDICTION CENTER NORMAN OK
  0342 AM CDT MON APR 28 2008

 

VALID 011200Z – 061200Z

 

…DISCUSSION…
  MAJOR MID/UPPER LEVEL LOW — NOW EVIDENT IN MOISTURE CHANNEL IMAGERY FROM GULF OF AK SWD ALONG 140W TO NEAR 40N — IS FCST TO MIGRATE SEWD OVER NWRN CONUS AND SWRN CANADA THROUGH DAY-3…THEN REDEVELOP SEWD ACROSS CENTRAL PLAINS DAYS 4-5/1ST-3RD. BEGINNING ABOUT MIDDLE OF DAY-4…OR 02/00Z…CONSIDERABLE SPREAD BEGINS TO APPEAR BETWEEN OPERATIONAL MODELS AS SHORTWAVE DETAILS MORE STRONGLY IMPACT GEOMETRY OF SYSTEM AND SUBSEQUENT EVOLUTION. MREF GUIDANCE IS UNAVAILABLE…HOWEVER…STG CONSENSUS IS TAKING SHAPE AMONGST DETERMINISTIC ECMWF/SPECTRAL/UK PROGS REGARDING BASIC DAY-4 PATTERN– STG MID/UPPER VORTEX ALOFT…DEEPENING THEN OCCLUDING SFC CYCLONE MOVING ACROSS PORTIONS NRN KS/ERN NEB…TRAILING COLD FRONT MOVING SEWD OVER SRN HIGH PLAINS…AND DRYLINE SSWWD FROM LOW ACROSS PORTIONS CENTRAL/ERN KS…CENTRAL OK…AND N-CENTRAL OR NW TX.
RETURN FLOW MOISTURE MAY BE SUFFICIENT TO SUPPORT WIDESPREAD SVR POTENTIAL FROM NEAR AND E OF SFC LOW SWD TOWARD ARKLATEX/SE OK REGION. DEEP-LAYER LOW IS FCST TO OCCLUDE DEEPLY AND BEGIN FILLING DAY-5/2ND-3RD…WITH TOO MUCH PROG SPREAD FROM THEN ONWARD TO ASSIGN ADDITIONAL SVR-DAY AREAS.

 

..EDWARDS.. 04/28/2008

Flight from Slovenia towards Dallas

We had an exchausting and long 14 hours flight from Slovenian airport Joze Pucnik through Paris Charles De Gaulle airport and continued towards Dallas/Fort Worth International airport. Here are some of the tenths of photos I took during our flights.

Aerial view over Julian Alps and Triglav at sunrise…

Julian Alps

The central Alps over Austria…

Julian Alps

View over central and eastern French coutryside was absolutely spectacular, color contrasts were really impressive!…

Colorful French countryside

View over Paris…

Paris, France

Shallow convection over coast of England…

Shallow convection

Small gravity waves over Altocumulus deck south of Ireland with some shallow convection and cumulus clouds over continental Ireland…

Small gravity waves

Flight continued just south of Greenland, which unfortunatelly was not visible due to stratus deck below, but we had a great view over Newfoundland in Canada with these incredible spiral bands of icebergs just east of the coast…

icebergs in spiral bands

Detailed view over the icebergs…

icebergs

Small glacier more to the west…

Glacier

One of the view over Dallas…

Dallas

Amazing view over Interstate I35 going through Dallas/Fort Worth…

Interstate I35 through Dallas

The next two days are expected to be calm, we will use them to visit some friends over here and to chill out after long flight. We definatelly need some sleep.

Later next week will likely be pretty interesting, models still predicting an impressive pattern through Apr 29th – May 2nd period. Stay tuned!