Gulf Surges, the Diurnal Cycle, and Convective Outflows as Revealed by the NCAR ISSs in NAME Richard H. Johnson, Peter J. Rogers, Paul E. Ciesielski, Brian D. McNoldy, and Richard K. Taft Colorado State University Acknowledgments: NSF, NOAA, NCAR ATD staff, and numerous students who worked at ISS sites

NCAR Integrated Sounding System (ISS) Vaisala GPS sounding system Enhanced surface observing station 915 MHz Doppler clear-air wind profiling radar Radio Acoustic Sounding System (RASS) 3 ISSs used in NAME 1 GLASS sounding system ISS Trailer, Los Mochis

NAME SOUNDING NETWORK PUERTO PEÑASCO BAHIA KINO LOS MOCHIS LORETO 3 ISSs 1 GLASS

N GULF S1 (IOP2) S2 (IOP3) 2004 MayJuneJulyAugSep PRECIPITABLE WATER ( °W) (NCEP Operational Analysis) HURR JAVIER HURR HOWARD TS BLAS (IOP10) TS AGATHA HURR CELIA HURR DARBY HURR FRANK TS GEORGETTE HURR ISIS Moisture surges and tropical waves, cyclones

BLAS DARBY FRANK GEORGETTE HOWARD ISIS JAVIER CENTRAL GULF 700-hPa V WIND (15-25°N) Easterly Waves During NAME EOP May Jun Jul Aug Sep CELIA

L TROPICAL STORM BLAS YUMA ●` ● MAZATLAN Heat Low 1004

TS BLAS QuikSCAT Winds HURR JAVIER HURR HOWARD TS GEORGETTE N GULF S GULF 13 JULY HURR DARBY? HURR FRANK V

BLAS 13 July Z LOS MOCHIS BAHIA KINO PUERTO PEÑASCO

● LOS MOCHIS ISS

MIDNIGHTNOON SURGE GUST FRONT 4-hPa rise

00 UTC GUST FRONT SURGE PEAK km

● BAHIA KINO ISS

7 hPa rise, but over longer period SURGE 3-hPa rise NOONMIDNIGHT

PUERTO PE Ñ ASCO ISS ●

SURGE GUST FRONTS 3.5-hPa rise NOONMIDNIGHT

km surge (RASS shut down at night due to noise impact on local populace)

4-hPa additional rise SURGE CONTINUES NEXT DAY, PEAKING AT NIGHT NOONMIDNIGHT

NOONMIDNIGHT PRESSURE MAXIMUM, 8 hPa INCREASE OVER 2 DAYS

Puerto Peñasco Bahia KinoLos Mochis Pressure rise signature progresses up the Gulf (8-10 h from Los Mochis to Puerto Peñasco) m s -1 propagation speed! Pressure signature and speed characteristic of an internal bore or mixed Kelvin wave–bore (e.g., Ralph et al. 2000) 7-8 hPa rise

Altair 12/20 – 13/04Z Altair 12/20 – 13/04Z

Puerto Peñasco 13/12 – 13/18Z Puerto Peñasco 13/12 – 13/18Z

● ● ● ● ● PEAK WINDS NEAR THE SURFACE IN THE NORTH …PEAK WINDS ELEVATED IN THE SOUTH GULF-// WINDS

● ● ● ● ● COOLING ASSOCIATED WITH SURGES… PRINCIPALLY CONFINED BELOW 700 hPa LASTS FOR 3-4 DAYS PRINCIPALLY CONFINED BELOW 700 hPa LASTS FOR 3-4 DAYS ELEVATED IN S FOR FIRST SURGE

Rain moved northward along coastal plain and into AZ with surge 24-h totals, July

UTC NOONMIDNIGHT EOP-MEAN LOW-LEVEL WIND DIURNAL CYCLE (7 JUL – 14 AUG) EOP-MEAN LOW-LEVEL WIND DIURNAL CYCLE (7 JUL – 14 AUG) PP BK LM Strong low- level jet at PP, much weaker at BK, absent at LM (Douglas 1995) Sea breezes Puerto Penasco Bahia Kino Los Mochis Weak land breezes, nocturnal offshore convection near S- Pol

S-POL RADAR 3 Aug UTC S-POL RADAR 3 Aug UTC NOAA-ETL PROFILER

Summary and Conclusions ISSs successfully documented many aspects of NAM along Gulf of California, including characteristics of surges July 13 surge associated with TS BLAS, preceded by downdraft outflows from SMO convection Peak surge winds on 13 July descend from 1.2 km AGL at LM and BK, to near 700 m at PP, maximum wind  20 m s -1 at Puerto Penasco; convective outflows are shallower (peak winds near 300 m) Pressure rises  3-4 hPa over 8-10 h period of surge, followed by additional  4 hPa rise over next 1-2 days (2-3°C surface temperature drop); initial P-rise signal moved rapidly up Gulf (  m s -1 )  internal bore, mixed Kelvin wave-bore? (awaiting more data)

Summary and Conclusions (cont) Surge on 13 July led to increased TPW and rainfall over southwestern US Diurnal cycle of PBL winds varies from south to north; prominent nocturnal LLJ in north, absent in south; prominent afternoon sea breezes at BK and LM; weak land breezes at BK and LM, coastal offshore convection near S-Pol Results are preliminary; further analysis awaits additional surface, pibal, and sounding data

(Ralph et al. 2000)

(Nuss et al. 2000)