Watching For the Monsoon

[Aslkahuna]

All week I have been watching the trends of the models and elsewhere to see if I would have to update my onset forecast for this year's monsoon which I outlooked for 6-11 July. The current trends suggest that I will probably not have to do that after all. The GFS is indicating that we'll be on verge of onset from July 4th through 8th with the model indicating that we'll be in monsoon flow conditions by the 8th. The monsoon moisture boundary is also expected to be in SE AZ as well. The pattern at H5 is classical monsoon by the 8th so it will be a matter of how right the model will be. The GFS has been consistently indicating monsoon onset in this general time frame since a few days ago so the consistency is a good sign at this point. One factor that could affect this would be Tropical Storm Carlos though the runs suggest that it should turn away from the Coast after about 72 hours. Another possibility exists that we could get a "dry" start in PHX and TUS if we were to get a low level surge in moisture sending dewpoints up but resulting in no rainfall. This could occur as the Thermal Low intensifies as the Upper High shifts over us early in July. This would be the false start I indicated that could happen prior to actual onset and would be over the Deserts but not in the monsoon zone of SE AZ.
We are watching and hopeful but one point is that the models are not indicating a strong onset so no black wall roaring up from Mexico this year.

Steve

[M2]

Our 'Soons are proged to start somewhere between July 15-20 but
anything goes this year.... Just don't think we'll get 2" of rain/month
like Tuc normally does during the monsoon. They've been drilling and
carrying news reports on the local news regarding the upcoming 'soon,
but the major newstory was from down in Tucson where they practiced
helicopter rescues with my old buds from DPS - a haul line lowered into
the lake to hoist out a stranded 'victim' over to dry land
Ah....to be flash-flooded once again

Hopes riding high. Skywarn TBD :Fade-color

[Aslkahuna]

The ECMWF has also come on board with the GFS and both are indicating that the monsoon will start either at the end of the Holiday weekend or a couple of days afterward. One problem the GFS indicates is that the start will be followed in about 5 days with another trough coming across giving us SW winds and dropping the moisture back south. This is actually a fairly normal pattern as onset lasts about 5-7 days followed byt the first "break" which lasts 3-5 days after which we get our first really severe event of the season and then we are off to the races. So now it's wait and see. One curious fact about the monsoon here, although July 4th is often given as the average start date, it has rained only 6 times on the 4th since I began keeping records here in 1987. From a rainfall standpoint (and the rains usually begin the late afternoon of the first day of high dewpoints) July 5th is a better start date here. Though it actually all depends upon that wind shift (ah, just heard the rumble of thunder).

Incidentally, the "victim" in the training session was none other than KVOA-4's chief OCM- Jimmy Stewart.

Steve

[Arizwx]

LOL!!!
I was talking to Jimmy the other day...we have much in common..#1 he is a Gen Aviation Pilot...#2 He's a baseball nut.
He started out in Detroit(#5 Market) for WXYZ Ch7 ABC DTW Afflialite..as a cub reporter..anyone with that background in a Top Ten Arbitron Market earns my respect immediately./.
He had some majot difficulty tho figuring out DBz to VIP 3-4etc which is Doppler vs Aircraft Indices for Trstrm Severity...He has it down now..I assure you, he owes me a Margarita at Cantina Guadalarja for that..still waitin'.
The 'Soon is incoming ..dews were well over 55F on Fri..approaching that today with a moderate but very consistant and useful heat blast.106.7F on Fri reaching for 107 today.......
As a good buddy in Nogales once said:
"DJ..It's the Season Mi Amigo!' 105F/Dp53/Smoke/Haze/Slack Wind/Strong Iversion layer&Digital remix of"Inna Gadda de Vida" by 'IronButterfly on the CD'(long version..The BEST Drum Solo ever recorded. circa.1967.)Last time I played it..I was inbound 'Downtown Hanoi'.
Steaks and "Cerveza frio 'Pacifico del Mazatlan.,S.A.,de C.V.' ready for the hot AZ Eve poolside..workin' the Tan baby.
'Cuts Like a Knife But It Feels So Right'~Bryan Adams~

[Aslkahuna]

on their AFD is trending towards the holiday for start and the satellite imagery is showing the pre monsoon buildup of activity along the Sierra Madre so it's about 7-10 days away now. The current moisture will be chased out as the Upper High reconsolidates overnight into a less favorable location and orientation. We had high basers today which kept us from hitting 100F but we are definitely in Sierra Vista's version of premonsoon heat. It now depends upon three factors, the location and orientation of that Upper High, whether or not we can get any big MCS' close enough to send deep outflow our way and finally what will be the effect of the depleted soil moisture conditions to our east and southeast.
Those will be key for the onset.

Steve

[M2]

Ran around the University down in Tucson today and the DPs/heat were up for sure...
not as hot as the 112F again in Phx but it was hot enough. The smoke
from both fires (Aspen & HelenII) seemed to infiltrate Tuc again this
evening...and the glow of the backburns on the backside of the Catalinas
lit up the ridges with a smokey red glow. Great view from La Cholla and
Tangerine Roads. See they are sending more and more of the firefighters
home and just allowing it to burn - and take care of the job that thinning
and maintenance should have over the years. And the Spotted Owl habitat
on the Rincons were toasted so the pseudo-environmentalists won't be
able to use that as an excuse there anymore. Doesn't matter which fire
was started by lightning and which by humans - the effect was the same.
It's taking care of the job that should have been managed for decades...
the trouble is - it took ALL the repeaters on Radio Ridge and
melted/twisted the metal, destroyed the buildings and took out the
communications of the Dept of Public Safety, Feds - everyone. Only Pima
County saw the disaster coming and disassembled and removed their
equipment before the fires converged & hit the Ridge - twice. Ouch.

If the monsoons come early, we'll all rejoice. Don't know if they'll get up
to this part of the State in the same efficient timeframe. We need outflow
boundaries from Tuc/Ajo in the South and White Mountains in the East to
kick-start us here....We're ready though

Must have been a sign; heard the 14 minute drum solo a few days ago and played along
on the steering wheel...sign of the 'Soon(er) Rather Than Later" ?

:Fade-color

[azskyman]

Although our last rainfall here fell on tax day, April 15th, I am at 6.67" for the year. As always there is a lot of debate about the heat island of Phoenix and the added ingredient is heavier than normal foliage we enjoyed this spring.

The monsoon arriving within the next ten days will be welcome of course for their contribution to the long term drought and for the occasional cloud cover that will shield us from summer's most intense sunshine.

I've been watching the daily percolation of CB to our east and north, but until I can see it down your way in Oro Valley and Sierra Vista, I do not figure it has yet arrived.

[Arizwx]

It's hot already..Rh is incoming,See some nice CB to the SSE,Looks like Agua Prieta,MX..
Checked the data for TIA;

http://www.wrh.noaa.gov/cgi-bin/wrhq/Ge ... TUS+Column

Monsoon Info..BTW..for newbies and those of us experinced,great info!

http://www.wrh.noaa.gov/tucson//

and the local EMX 88-D..c'mon "mexsoon'..let's ROCK!!!NOTE the shift in pattern,more ESE..yes!

http://www.wrh.noaa.gov/radar/loop/DS.p ... kemx.shtml

[Colin]

I'm hoping for you AZ! Keep us updated!

[azsnowman]

Startin' to sound pretty good!

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 PM MST SUN JUN 29 2003

.SYNOPSIS...HIGH PRESSURE WILL REMAIN IN PLACE OVER THE SOUTHWEST
THROUGH MUCH OF THE COMING WEEK. EXPECT ISOLATED SHOWERS AND
THUNDERSTORMS EACH DAY...SLOWLY SPREADING WEST AND NORTH FROM THE
WHITE MOUNTAINS AND MOGOLLON RIM TODAY...ALL THE WAY TO THE KAIBAB
PLATEAU BY MID WEEK. HIGH TEMPERATURES WILL REMAIN NEAR NORMAL.

.DISCUSSION...THE MID LEVEL RIDGE WILL SHIFT TO NEAR THE FOUR
CORNERS AREA FROM MONDAY INTO WEDNESDAY...WITH SOUTHEASTERLY FLOW
DEVELOPING. THE CORRESPONDING INCREASE IN MOISTURE SHOULD STEADILY
INCREASE THE AREAL COVERAGE OF ISOLATED CONVECTION EACH DAY THIS
WEEK. IN FACT...A WEAK TO MODERATE SURGE OF LOW-LEVEL MOISTURE HAS
MOVED IN FROM THE GULF OF CALIFORNIA. DEW POINTS WERE UP AND
TEMPERATURES WERE DOWN ACROSS A WIDE AREA OF THE LOW DESERT THIS
AFTERNOON. IF THIS MOISTURE SURGE PERSISTS THE MID-LEVEL RIDGE WILL
BE IN A PERFECT POSITION FOR AN UPSWING IN CONVECTIVE ACTIVITY
ACROSS NORTHERN ARIZONA. LOOKING AT THE POTENTIAL FOR MORE THAN JUST
HIGH BASED DRY THUNDERSTORMS BY WEDNESDAY. BUT THIS DEPENDS ON THE
PERSISTENCE OF THE MOISTURE SURGE AND IF CONVECTIVE ACTIVITY
INCREASES OVER NORTHWEST MEXICO. ASIDE FROM THE CONVECTIVE
POSSIBILITIES...AIR MASS WILL CONTINUE TO BE VERY HOT...WITH LITTLE
SYNOPTIC WINDS.

IN THE EXTENDED...THE MID TO UPPER RIDGE WILL REMAIN IN A FAVORABLE
POSITION FOR MOISTURE TO MOVE INTO NORTHERN ARIZONA FROM THE SOUTH
AND SOUTHEAST. AS A RESULT...WILL CONTINUE AFTERNOON AND EVENING
THUNDERSTORM ACTIVITY INTO NEXT SUNDAY.

Dennis

[Stephanie]

I hope that your forecast holds up Steve! Sounds promising!

[azsnowman]

--------------------------------------------------------------------------------

AFDFLG

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
235 AM MST MON JUN 30 2003

.SYNOPSIS...HIGH PRESSURE WILL REMAIN IN PLACE OVER THE SOUTHWEST
THROUGH MUCH OF THE COMING WEEK. EXPECT ISOLATED SHOWERS AND
THUNDERSTORMS NEAR THE NEW MEXICO BORDER TODAY...THEN SLOWLY
SPREADING NORTH AND WEST TOWARDS THE KAIBAB PLATEAU BY MID WEEK.
HIGH TEMPERATURES WILL REMAIN SLIGHTLY ABOVE NORMAL.

.DISCUSSION...SURGE FROM SUNDAY WILL LIKELY NOT AFFECT CENTRAL OR
NORTHERN ARIZONA AS INCREASINGLY WESTERLY BOUNDARY LAYER FLOW WILL
SHUT DOWN THIS SOURCE LATER TODAY. THIS WILL LEAVE US WITH MORE OR
LESS THE SAME AIRMASS AS YESTERDAY...WITH MID LEVEL MOISTURE LEADING
TO ISOLATED DRY CONVECTION OVER THE EASTERN ZONES THIS AFTERNOON.
MORE OF THE SAME TUESDAY BEFORE MID LEVEL FLOW SHIFTS TO MORE OF A
SOUTHEASTERLY DIRECTION BY MID TO LATE WEEK. THIS FLOW DEVELOPS AS
THE HIGH PRESSURE SYSTEM AND RIDGE AXIS SHIFTS NORTHEAST INTO WESTERN
NEW MEXICO...OPENING THE DOOR FOR INCREASING MOISTURE. MODELS STILL
LEAVING US VERY DRY BELOW 500 MB...SO ALTHOUGH CONVECTIVE CHANCES
WILL PUSH BACK WEST AND NORTH...COVERAGE STILL IN THE ISOLATED
CATEGORY AND MOST STORMS WILL BE DRY. IN SUMMARY...SLOWLY INCREASING
MOISTURE WILL SPREAD CONVECTIVE CHANCES BACK WEST AND NORTH THROUGH
THE WEEK. WILL WATCH HIGH POSITION CAREFULLY IN THE COMING DAYS AS
ANY FURTHER NORTH AND EAST POSITIONING WILL RESULT IN MORE OF A
MOISTURE INCREASE. PETERSON.

[Aslkahuna]

across SE AZ today with YUM at -6C DP and TUS at +11C. The Dryline at 850mb extends NE from about the Sells area to just NW of TUS and thence to about Santa Fe (except at elevation). This will be the focus area for what convection occurs as it mixes out and pushes southeast with the afternoon winds off the low deserts-will probably end up east of Sierra Vista before reversing again tonight. This has been the pattern each day for the past four days with dewpoints above monsoon criteria in the morning but going well below in the afternoon as we mix out to drier air above. Overall flow pattern is not favorable for a deep moisture surge at this time. Incidentally, for those who still think AZ gets only dry heat, Yuma's dewpoint yesterday at 8 am was 76F and it never dropped below 68F all day yesterday-this was the moisture surge referred to by Flag, but it was too shallow to make a difference.

Looking at the GFS, ECMWF, ETA-X, and the NOGAPS through the holiday, all of the models suggest that the H5 flow will remain rather light and east to southeast but that flow in the lower layers will not be monsoonal in character. This means that most moisture import will be mid level with the "sloshing" pattern with the pooled low level moisture through this coming week meaning that isolated to widely scattered boomers will be the ticket through the week and into the weekend. After that we tend to diverge with the models available (ECMWF, GFS) through Day 10 with the EC putting a strong H5 High right in perfect position on July 5th and with us on the monsoon boundary out to Day 10. The GFS is not as robust with the H5 High and in fact begins to flatten it out as a trough comes across the PAC NW so that by Days 10-15 we are in dry SW flow with a rebound happening by Day 16. What this translates to is a possible but weak monsoon start during 4-8 July followed by a strong break with gusty winds and dry conditions 9-14 July and then quite possibly all H*** breaks loose shortly thereafter as the rebound occurs in such a manner as to unleash a severe weather event.

Steve

[M2]

Great analysis Aslkahuna If that holds, then the monsoon here in
Phx should officially start "after" yours and Tucson's, in whatever timeframe.
Looking forward to your outflow boundaries...and the boomers coming down
the rim from Snowman's way too. We'll keep our eyes on the midlevel
moisture...and wind reversal....but as you say, when it kicks in - look out.
Last year we had 3 big (severe) storms in one week then it just about
tuckered out for the rest of the summer. David, oh David!....- time to call the
dance troupe together again with Pburgh, Raine and Steph... Now no fair
practicing down your way to bring in TS Bill.....

[azsnowman]

WILD CARD IN THIS SCENARIO IS THE FACT THAT MUCH DEEPER MOISTURE
POOL TO OUR SOUTH COULD BECOME MUCH MORE ACTIVE THE NEXT FEW DAYS.
THIS WILL IMPROVE THE POSSIBILITY OF MCC TYPE ACTIVITY TO THE
SOUTH...WHICH MAY PUSH DEEP OUTFLOWS INTO ARIZONA. ALSO...THE GULF
OF CALIFORNIA REMAINS PRIMED FOR A SURGE...ESPECIALLY AS COOL
OUTFLOW DRIVEN AIR AND DEBRIS CLOUDS WILL EXIST OVER THE SOUTHERN
GULF THIS MORNING. THESE IMPORTANT MOISTURE SUPPLEMENTS WILL HAVE
TO BE WATCHED CAREFULLY AS THEY COULD LEAD TO MUCH MORE WIDESPREAD
CONVECTION. FOR NOW...WILL STICK WITH THE 20-30 POPS SCENARIO WITH
MAINLY HIGH BASED CONVECTION UNTIL SOMETHING CHANGES. TEMPERATURES
WILL REMAIN ON THE WARM SIDE WITH THE STRONG RIDGE OVERHEAD AND
SYNOPTIC SCALE WINDS WILL BE MINIMAL. PETERSON.

[Aslkahuna]

is assessing the effects on sun parched Drought dried ground upon the moisture in the lower levels. The pattern as it evolves indicates a trajectory from TX and the Plains initially-areas which have been experiencing the same drought we have as has Chihuahua and Sonora. It's great to speculate about MCS's but they have to form first which so far they have not been doing or have been doing so too far south. Another problem is the fact the Mexican Monsoon, which must be established before we can get ours, is not developed as well as it should be at this time of the year. My area of concern in all this is far SE AZ of course in the area east of the western boundary of the Divide which is marked by the Santa Ritas. A Gulf Surge, which is quite possible, would be of no value to us here since it would not reach us. This raises the possibility that the dewpoints could reach monsoon criteria in PHX and TUS and western AZ but not here. But without mid level moisture above 800 mb and the dynamics associated with the true monsoon flow that would not result in a great deal of activity or rainfall. In truth, there is one thing that has been missing from this "buildup" to the monsoon and that's seeing the tops of those big CB over the Sierra Madre every afternoon that inch closer each day until-WHAM!

Steve

[Aslkahuna]

Tucson in their AFD this afternoon also noted the same thing I did about the trajectory of the airflow saying that it's from Nrn NM rather than from Old Mexico and the moisture is more limited there than in Mexico. Thus they are going for no grade non soon conditions with isolated activity through the Holiday. In what has to be a low and outside one, I was reading an article about the rehabilitation efforts scheduled to begin shortly in the Aspen fire burn area and they have a forecast of July 18th for the start of the monsoon which is well later than I'm expecting and they have been apprised that it will be a slow start. July 18th would be the latest start down here since 1986 except possibly for 1987 (for which I don't have temperature data. Last year, we started here on the 8th and I'm still sticking with my start period as indicated on my homepage.

Steve

[Aslkahuna]

Next Week.

Steve

[Aslkahuna]

The H5 High is in a good location but the flow below that level is most unfavorable with the H7 High over Northern Baja and the Sea of Cortez. Consequently, the windflow from H7 on down is NW which, besides aggravating the Aspen Fire situation, is keeping the moisture in Mexico at Bay. The 850mb analysis clearly shows the monsoon moisture boundary down in Sonora not far from the Frontera. July 4th is the nominal start date for the monsoon according to PHX and TUS NWS (as I have pointed out, the 5th is a better date down here) but according to the latest model runs, it's not going to happen as the H7 High does not move until next week. The latest AFD out of TUS now specifically states that the monsoon will start late again this year-last year it was on the 8th and this year will probably be in the same time period.

Steve

[Stephanie]

It looks like NM has "isolated thunderstorms" in the forecast. Is this a good sign or is their monsoon totally unrelated to how yours develops?