April 2018- April To End Cooler/Drier Than Normal

[DoctorMu]

Like night and day in CLL.

We had a pretty fierce T-storm ahead of the front and about 0.25 in of rain.


Yesterday was a yucky, humid 70°F dew point day with a high of 84°F while today is colder, overcast, and blustery - 44°F at 2 pm! winds gusting to 30 mph. Wind chill of 34°F. lol

40°F dropoff. Wow.

That's Texas weather! A happy medium would be nice, but I'd have to move back to North Carolina for extended periods of that. Long springs and Indian summers.

[DoctorMu]

Now down to 42°F, a 42° falloff from yesterday.

[jasons2k]

Just got home from being at a baseball tournament all day. It was pretty cold, especially as the day wore on. It's not supposed to be like this in April. It's 48F here now.

[srainhoutx]

Good morning from a cloudy/chilly S Padre Island. It looks like clouds held temperatures up across SE Texas overnight with reading in the low to mid 40's to 50's near the Coast. A return flow begins late this afternoon into tonight bringing a warming trend, but somewhat brief as another front arrives Tuesday.

Looking to the last half of the work week, the Ensemble Guidance is in good agreement that a deep upper trough with a vigorous storm system begins to organize to our NW bringing a chance for strong to possibly severe thunderstorms back into the end of the work week. The Storm Prediction Center is Outling a Day 6 Highlighted Risk area just N and E of Metro Houston. It appears we are in a pattern capable of bringing stormy weather every few days at least into mid to late April.

[jasons2k]

On yesterday, the NWS had me forecast at 73 today. Then they lowered it to 69.

My high today was 58.

[Katdaddy]

Cloudy skies and some patchy drizzle across SE TX early this morning with temps mostly in the mid to upper 50s. Low rain chances today ahead of the next cool front tonight. The sun and warmer temps are on the way for Tuesday through Thursday. Thunderstorm chances will enter the forecast beginning Thursday night ahead of the next cold front. Its possible strong to severe storms may be a threat Friday afternoon and Friday night.

[jasons2k]

Area Forecast Discussion
National Weather Service Houston/Galveston TX
946 AM CDT Mon Apr 9 2018

.UPDATE...

Surface analysis this morning still has weak high pressure over
the area with light NE winds. Another frontal boundary was taking
shape over the central Plains with high pressure over the northern
Plains. Aloft...upper level pattern remains somewhat zonal across
much of the U.S. with a weak ridge over the western U.S. and a
short wave trough over the Rockies. Radar shows light rain/drizzle
over much of the area with cloud skies due to isentropic lift.
VAD wind profile from the radar shows NE winds turning to SW with
height and most of the SW flow in the 925-850mb layer consistent
with isentropic lift.

Overall thinking is that clouds/rain/drizzle should continue for
much of the area throughout the day. Frontal boundary from the
plains should push into the area overnight with northerly flow
tomorrow as high pressure builds south. Only changes to the
forecast were to make minor adjustments for rain chances and
temperatures today.

[srainhoutx]

It sure looks like we are somewhat stuck in a pattern that continues to dig a very deep and by April standards, cold and dry regime. The afternoon Updated Climate Prediction Center Day 6 to 10 Outlook and Day 8+ Analogs suggests rather chilly air with a persistent NW flow aloft this weekend into next week looks reasonable with dry conditions for the most part.

[jasons2k]

Looks like more capping issues this Friday...again!!

[Katdaddy]

A narrow line of light showers have moved offshore and will be followed by mostly sunny skies, lower humidity, and highs in the mid 70s to low 80s the next few days. Rain and thunderstorm chances arrive Friday through early Saturday with the next cold front. Some of the storms will possibly be strong to severe but will be followed by clearing skies Saturday morning leading to a nice weekend with more sun.

[srainhoutx]

Looking ahead to Friday, I continue to see issues with a capping inversion that may limit thunderstorm development across Metro Houston keeping the greatest threat for strong to possibly severe storms to our NE across the Piney Woods of East Texas. The Main storm system is just a bit too far North for any real significant impacts to SE Texas. Warm air streamer showers ahead of the front looks like the mostly solution as of Tuesday morning with some higher chances of somewhat heavier rains associated with the cold front late Friday night into early Saturday morning. We will continue to monitor for changes throughout the week.

The biggest story in my opinion id the unusually strong Upper Low over the Central Plains expected Friday/Saturday which appears to be 3 standard deviations below normal mid April climatology. No what does that mean? There is a lot of very chilly air that will drop into Texas behind the front bringing daytime highs struggling to reach 60, if we completely clear out behind the front. As High Pressure settles across the Region early Sunday morning, some chilly mid to upper 30's may be possible across our Northern Zones...again if we have clear skies and winds totally relax. While its been a while since we have seen such cool and dry weather in mid April, it has happened before in recent memory. We have seen sleet in April about 10 to 11 years ago and even an Easter snow fall, even if it was light on the accumulation side.

ECMWF EPS:

GEFS:

[BlueJay]

While we are contemplating what may happen in the weather department for this coming weekend - let's enjoy this beautiful day! It is good to see the sun again.

[Katdaddy]

This morning's AFD update mentions the NAM showing a weaker cap. It will be interesting if the other models begin trending toward a weaker cap during the next few days.

The 12Z forecast guidance is still coming in but early look at the
NAM shows a weaker cap than the GFS/ECMWF showed in yesterday`s
runs. NAM`s storm environment shows parameters that support
organized storm structures like supercells. Still some time to
work out the details in the next day or two. Overpeck

[jasons2k]

Either our climate has changed, or we are stuck in some very strange long-term pattern. For the last decade or so, we just can't eke out a normal spring storm season.

If the winter is cool, then the shelf waters cool as well and provide low clouds all day preventing any sort of instability (that was a new one for me too, after watching the dryline in North Texas for 20 years, never once heard an issue with 'shelf waters' limiting instability...anyway, I digress).

If the winter is warm, then we get a persistent cap and no matter now much sun we get...all the 'energy' is too far to the north.

What is going on? We've always had unusual weather....but it seems like the new climate norm for us is almost monsoonal, similar to India. Oppressive and dry for months until the tropics finally give us some relief.

It's not supposed to be like this every spring.

[Texaspirate11]

Let it stay "cool" and "Strange' thru hurricane season
Although I love the heat...I"ll take this for this season....

[Katdaddy]

Temps mostly in the 40s and 50s this morning with a beautiful sunny warm Spring day ahead for SE TX.

[srainhoutx]

The Storm Prediction Center has outlined a Slight Risk for severe thunderstorms Friday in their Day 3 Outlook, but there remains a lot of uncertainty as to a capping inversion associated with increase SW flow aloft ahead of an advancing dryline/cold front near Central Texas Friday afternoon. The NAM/ECMWF keep that cap strong across the area except for our far NE zones in the Piney Woods of East Texas while the GFS has a couple of embedded disturbances riding across our Region from the SW to NE cooling the atmosphere at the mid/upper levels erode the cap and allowing storms to develop. Until we see more consistency, it's a safe bet as of Wednesday morning to expect capping issues and the possibility of warm air advection streamer showers beneath the cap. Since we are still 72+ hours away from the cold front actually arriving, we will continue to monitor in case further data increases our chances of strong to severe thunderstorms developing. Stay Tuned!

[tireman4]

Tor Con of 4 Friday....

[tireman4]

FXUS64 KHGX 111444
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
944 AM CDT Wed Apr 11 2018

.UPDATE...

High pressure over the Mid-South should continue to move east
today allowing for southerly winds to develop over SE Texas later
this afternoon. Temperatures look on track to reach the upper 70s
to low 80s today for high temperatures. Moisture return looks on
track for Thursday with the potential for severe weather over the
area on Friday. That will be the main focus of the forecast update
in the afternoon.

Overpeck

[jasons2k]

A very nice and long discussion, basically all to say, we don’t know yet. They are hedging on the slower/wetter Euro/NAM combo, but not sure. Wait and see...

Area Forecast Discussion
National Weather Service Houston/Galveston TX
345 PM CDT Wed Apr 11 2018


.SHORT TERM [Friday Through Saturday]...

Let`s just get to the point. What is going to happen Friday and
Friday night with regards to the severe weather potential? SPC has
slight risk of severe for I-10 north with a smidge of enhanced
over Houston/Trinity/Polk Counties. I really do not see anything
in the model data that suggests anything different.

- Synoptic Overview - 18Z Friday to 00Z Saturday an upper level
low that is now moving towards the Pac NW should reach the
central Plains. Strong banana like jet streak stretches from
near Kansas City back through OKC and then SW towards west
Texas. There is also another weaker jet that moves out of Mexico
towards SE Texas during this time. The elevated mixed layer
should be moving over much of the area as all three
NAM/GFS/ECMWF show 700mb temps of 8-11C over the southern half
of the forecast area. Closer to a College Station to Crockett
line, 700mb temps are closer to 6-8C and that is also where
models develop QPF and storms. From 00Z to 12Z Saturday this
upper low moves across the central Plains with the jet now
edging close to SE Texas. Second jet coming out of Mexico
spreads across the Gulf so possible to get a slight coupled jet
structure and added divergence over the region. As such, 700mb
temperatures decrease over the area and NAM/ECMWF generate QPF
along the advancing dryline/cold front combination. GFS is still
faster with the dryline and then the front so that it is drier
than the other models. Given the orientation of the trough and
the jet at this time, lean more on the ECMWF/NAM which are
slower with the front.

- Mesoscale Overview - while there are some subtle differences in
the models with regards to the synoptics, there are even more
differences on the mesoscale. Even 3 days out the mesoscale
details are a challenge to sort out but here it goes. No doubt
there will be moisture and even deep moisture with model
soundings showing moisture up to 800mb. Instability in the 18Z
Friday to 00Z Saturday time frame looks strongest where the
elevated mixed layer is the weakest thanks to some cooling aloft
with the jet and trough structure but also enough of an elevated
mixed layer for an inversion at 800-700mb that supports steep
lapse rates. CAPE values are still in the 2000-3500 J/kg range
for both the GFS/NAM and the ECMWF showing LI around -8/-9 so
for the most part consistent with the other models. The biggest
differences in the models will be the position of the dryline.
The GFS still brings the dryline east of I-35 while the
NAM/ECMWF hold it closer to I-35 or even a bit west. This has
implications for the Friday late afternoon round 1 of storms and
possible areas of initiation. Just too soon to sort out those
details. As for storm mode...still thinking possible supercells
with deep layer shear close to 50 kts and low level shear around
20 kts given a strong LLJ. Headed into the overnight,
instability decreases some but still enough for severe storms
given the cooling aloft with the trough approaching. With the
front advancing, storms should still be linear but enough shear
to organize the line with some bow segments. Question will be
how much the elevated mixed layer affects convection as the line
very well could be a broken line of cells. Still lots of details
to sort out and still concerned about upper level forcing being
out of phase with best surface forcing and severe parameters.

- Bottom Line - Round 1 of severe/strong storms possible Friday
afternoon/evening from Brenham/Huntsville/Lufkin northward
depending upon strength of the elevated mixed layer. Round 2 of
severe/strong storms along the front overnight across the whole
area. Elevated mixed layer may limit strength of storms. Given
expected storm modes of supercells and then a squall line -
there very well could be a tornado threat Friday afternoon along
with hail/damaging winds. Tornado threat cannot be completely
ruled out overnight with a line of storms, but hail/damaging
winds more likely threat. But what about heavy rainfall?
Precipitable water values will reach 1.7 to 1.9 inches but since
storms will be moving quickly across the area, any kind of urban
flood threat remains low.